Decima, the Stormsinger

Enrage: 10 minutes.
Tank: Proximity
Required: Burst healing, ,
Recommended: , some crowd control

Decima, although a very flashy encounter, has very little randomness; a good strategy and positioning will make short work of this Titan of thunder. Although she will turn to attack the closest player with her auto-attacks, this fight also requires zero consideration towards tanking.

Her enrage timer is relatively tight compared to older raid bosses, and groups with lower damage will feel its looming presence in the last phase. Before taking on the Stormsinger, leaders should make sure their squad has a sensible composition, and ensure that the DPS players bring classes that they’ve practiced and are comfortable with.

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Squads will generally split up into two groups after the first phase of the encounter: one who generally stays near the boss (‘melee’) and one who has to bait a mechanic at regular intervals (‘ranged’). Although ostensibly a ranged mechanic, Decima will simply check for the five furthest players from her at specific points in her pattern, so after stepping out to bait this mechanic, the marked players can then walk back into melee range. In other words, there is no hard requirement for ranged damage on this encounter for any of the DPS players; just about any damage build can work for this boss fight!

For the squad’s healers, strong burst healing and is very important as the fight progresses. and , although not strictly required, are also expected from the support players in each subgroup in order to deal with some of the boss’s attacks. For the subgroup that is baiting the Arrows, we recommend a Heal Alacrity Scourge for its superlative application, with the other healer(s) being more flexible in their choice of build (the ones below are not the only good choices).

Squads fighting Decima can choose to either run two healers (with a DPS player such as a Virtuoso taking on the role of Kiter) or three healers (1 per subgroup + a heal Kiter). In either case, it is highly recommended that the Kiter brings a two-way teleport in order to avoid getting cut off by the Fences that are strung throughout the arena, especially in the third phase. This can be done with skills like Sand Swell, Shadowstep, or the Mimic Blink combination.

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Due to the Conduits being present for all phases of the encounter, we will begin the guide with a look at the mechanics that primarily affect them. Players looking for a look at how each phase plays out can use the Table of Contents to move to the relevant phase, and use the in-guide links to quickly jump to the explanation of any unfamiliar mechanics.

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A double or triple-charged conduit is the most pernicious mechanical failure in the fight and must be avoided through proper positioning for all squad members and some forethought from the Kiter when they move out for their Arrows.

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Decima will gain one stack of Peal of Harmony every time her health is brought down by 3% from its value at the start of each phase, usually leading to one or two extra conduits being charged with each cast of her Arrow attacks in the second and third phases (where this mechanic is most relevant).

Positioning themselves around this mechanic should be one of the primary concerns of the Kiter. Proactively powering up conduits closer to the boss group in the second and third phase will make the encounter much more manageable, while carelessly powering up conduits near the Arrow baiters (if doing a static positioning strategy) will cause them to struggle with dealing with both the Arrows and the Sparks (that they must avoid touching due to Galvanic Sensitivity).

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This mechanic does not deal high damage on its own, and three players can easily stack them with and some on top of the mitigation mentioned above; stacking all five is not advised in general. Players should avoid panicking with a Spread and walking backwards from the boss into a conduit, unnecessarily charging it up in the process.

Note: only blocks the effects of one of the Spread AoEs; any others will still hit players!

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This mechanic mainly affects the Kiter, but any players caught without for Decima’s crowd control will also have to deal with them.

In the third phase, one of the patterns has no openings for players caught outside the central ring to get back in, so without at teleport skill, they will have to wait on the other side of the fence until the pattern flips, possibly getting targeted with a Red Arrow!

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Due to Galvanic Sensitivity, all players besides the Kiter can and should soak (i.e. stand in) the Sparks in the first phase of the encounter, but in the second and third phase, only the boss (AKA ‘melee’) group are able to collect them without the heavy risk of a quick downstate.

More players in a Spark will cause it to dissipate more quickly; players shouldn’t simply solo Sparks, but instead try and clear them out with other squadmates unless going for a hero Spark that’s on the other side of the boss.

Larger Sparks, outside of their higher player requirement, also take up more space in the arena, which can make it very tricky for the sensitized Arrow-baiting players to path around them while still avoiding hitting conduits with their Arrow.

Note: Although Galvanic Sensitivity really hurts, the ticking damage from the Sparks does not apply immediately upon stepping in them and halting their momentum. In a pinch, players with the debuff (almost always the Arrow baiters) can wiggle in and out of a Spark in order to stop its movement without taking any damage!

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Phase 1 (100-75%)

In her first phase, players are introduced to the order in which Decima performs her attacks and spawns mechanics. This pattern stays mostly consistent throughout the fight, with slight changes and additions in the later phases:

1. Auto-attack combo
2. Orange Arrow
3. Jumping Knockback (and Jumping Knockforward)
4. Sparks (Green circles) and Red Arrow
   

As mentioned above, the Spread mechanic can overlap with either of the Arrow mechanics depending on the squad’s DPS.

Sparks will always follow the Knockback attack, while the Red Arrow comes after both jumping attacks conclude. This means Sparks may spawn before the Red Arrow if she chooses to do the Knockback first, then the Knockforward.

In all phases, if Decima collects 10 stacks of Charge from Sparks, the squad will wipe.

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The Kiter will bait out this Arrow in the first phase: in order to avoid powering up a conduit, they should quickly move such that the arrow is in-between two of the conduits. In the first phase, they should avoid stepping too close to the boss (telegraphed by the red ring around her) as this will give Harmonic Sensitivity; this effect adds an extra damage spike (to the tune of about 25% HP!) to the Orange Arrow attack.

Boon supports should give the Kiter special attention due to their being off the group during Phase 1 overall.

The other players in the squad should then move slightly around the boss to avoid getting hit by the beam and unnecessarily gaining Galvanic Sensitivity.

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Healers in both subgroups should always use one of their  or sources for this attack, but if access to these boons seems spotty, all players have a responsibility to Dodge (usually sideways) to avoid a nasty push, as this can cause many of the range-based mechanics to be baited incorrectly!

Note: Decima will always pair Seismic Crash with Earthrend, although whether it comes before or after is random.

Earthrend is another leaping AoE crowd control move (that will still instantly kill players under her!), however this attack only affects players on the outside part of the arena. Players should never be in range of this attack unless they were knocked away by Seismic Crash if it came before Earthrend; move quickly back to the boss in this scenario to avoid this mechanic.

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The Kiter must always bait out the Red Arrows in this encounter and be prepared to teleport behind a safe, uncharged conduit once the Arrow is on the field; this is their most important role. This is because the Fence patterns in the second and third phases prevent most of the players in the squad from easily moving behind a conduit in time, especially if their reaction time is slow.

Kiters should avoid moving too much horizontally once they have selected a conduit to hide behind, as players near the boss will have trouble avoiding the deadly Arrow while dealing with other mechanics otherwise.

For the non-targeted players, any Sparks that are inside the Red Arrow should always be left until after the boss fires her beam in almost every situation.

Note: Upon gaining a Red Arrow, the affected player’s character will sometimes call out “Need cover.” with both a voice clip and text bubble. Players will also gain a deep-red-colored border on their screen when targeted.

Bug: The Red Arrow can de-render on lower Character Model Limit settings, particularly for the targeted player once they’re at range from the boss.

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Intermission Phases

If her defiance bar is broken, Decima will be and Stunned for 10 seconds. Complicating matters, however, is that any Sparks that make it to the boss will completely regenerate the bar!

To help aid in Spark collection, upon entering an intermission phase, all players will immediately lose Galvanic Sensitivity, meaning the entire squad can safely soak them.

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If the boss’s defiance bar is not broken due to Sparks getting in, players should be quick to get stacked at around the 20-second mark of the phase in order to outheal the damage of the explosion and quickly pick up any downed players.

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Phase 2 (75-40%)

In Phase 2, the main change is the addition of four more Orange Arrows from the boss every time she charges up her Fluxlance, meaning that there is a lot more damage pressure on the group, a higher chance of a conduit getting charged up by an unaware player, and the forced application of Galvanic Sensitivity to more players (making them unable to meaningfully contribute to soaking Sparks).

She also now casts a gust of Wind with the quintuple Orange Arrow that, without , will forcibly rotate players for a set distance around the boss, heavily throwing off the positioning of players for both Arrow baiting and any late Spark collections! This Wind, along with the aforementioned Knockback, makes having two sources of for the healers to alternate between extremely powerful for this encounter.

The order of mechanics in this phase is (with Spreads at a staggered timing):

1. Auto-attack combo
2. Wind and 5x Orange Arrows
   
3. Jumping Knockback (and Jumping Knockforward)
4. Sparks (Green circles), Red Arrows, and 4x Orange Arrows
   

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In order to deal with both the boss’s Fluxlance attacks and the Sparks, the squad’s two subgroups should split up, with the Arrow baiters (‘ranged’ subgroup) standing and stacking at a short distance from Decima, all while positioning such that their Arrow will end up in-between two conduits to avoid powering one up.

The other (boss or ‘melee’) subgroup can stay on the boss, avoiding the Arrows while collecting any Sparks as they are released from conduits.

If doing the static positioning strategy, the Kiter, while remaining the furthest player whenever an Arrow is going to spawn, can attempt to position themselves somewhat counterclockwise from the rest of the Arrow baiters in order to avoid the Harmonious Thunder mechanic making Sparks spawn behind the Arrow baiters, therefore forcing them to sidestep these Sparks due to Galvanic Sensitivity. Otherwise, they can mostly stay with the Arrow baiters except for during the Red Arrow.

The second set of Arrows in her pattern will spawn a Red Arrow rather than an Orange one on the furthest player, which will be the first of the five to fire.

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These orange, numbered Arrows can be safely stacked in-between two conduits, outhealed, and out-Barriered, especially in Phase 2 as each beam attack comes out one at a time. As in the first phase, players without an Arrow should avoid getting unnecessarily hit by these beams.

If a non-baiting player is targeted one of these Arrows by accident, they should not panic and run around aimlessly; they should turn their camera to look behind themselves for the closest two conduits and stand in-between them. If this happens, note that this player cannot collect Sparks for 30 seconds due to Galvanic Sensitivity.

If Decima gains stacks of Charge, these five beam attacks will deal more damage! Boss group players must not slack on soaking Sparks in order keep the Arrow baiters healthy.

Note: Stepping in the faint red-outlined AoE near Decima will apply the Harmonic Sensitivity effect, which will apply additional damage to any one of her Fluxlance (Arrow) attacks.

Although this will make the first Arrow in a phase hit noticeably harder for any affected Arrow baiters, once hit by any beam this effect will be replaced by Galvanic Sensitivity and unable to be reapplied for 30 seconds. Since past the first phase, Arrow attacks are less than 30 seconds apart from each other, the baiters will never have to worry about this effect past the first beam hit of many in each phase.

This means that as long as players are gaining the target for every Arrow by moving out for a brief moment at the proper time in her pattern, players are not particularly punished for playing in melee even as an Arrow baiter.

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In Phase 2, this mechanic only affects players that are far out in the arena, meaning no players should be rotated as long as the Arrow baiters stand just outside of the small red AoE around the boss.

In Phase 3, this mechanic is arena-wide; although the squad’s supports should use whenever the first set of Arrows in a cycle spawns, players should always be prepared to be rotated. For the Arrow baiters, they must turn their camera to look behind themselves after the rotation to move their Arrow out of any conduits, while any melee players will need to find the Green Arrow and quickly move into it.

Note: In addition to the spinning arrows above the arena acting as a telegraph, whenever the Wind mechanic is cast, a raid-wide announcement will appear at the top of the screen that reads: “Violent winds approach!”

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Phase 3 (40-0%)

After a second intermission phase, the third phase of the encounter will begin, which only adds one new but impactful mechanic to contend with: the Green Arrow. At least five of the boss group players must stand inside this Green Arrow to avoid powering up the conduit on their side of the arena and Exposing the entire squad.

Furthermore, the standard Arrow mechanics have been changed to fire all at once, necessitating that the Arrow baiters spread out slightly in order to avoid becoming downed. Stacking two Arrows is generally fine even without , but stacking all five, especially if the squad is Exposed, will require massive and likely resurrection support as well.

Lastly, the Wind mechanic will now affect the center of the platform as well; the boss and Arrow subgroups will (with proper positioning) be rotated in the same direction. should be used on all players in order to avoid chaos for both the Orange and Green Arrows.

The pattern of mechanics for this final phase of the boss (with Spreads at a staggered timing) is as follows:

1. Auto-attack combo
2. Wind, Green Arrow, and 5x Orange Arrows
   
3. Jumping Knockback (and Jumping Knockforward)
4. Sparks (Green circles), Red Arrow, and 4x Orange Arrows

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Nothing should change too much for the Arrow baiting group (besides spreading out their Arrows slightly). As long as both crowd control abilities from Decima are dealt with, they can continue to follow the strategy the squad has decided on.

For the boss group, moving quickly into the Green Arrows is critically important, as well as collecting Sparks cleanly. Letting in Sparks will increase the damage of the Orange Arrows, making surviving a stacked hit much harder for the baiters later into the phase! Avoiding early Charges also makes the margin for error for missing Sparks greater as the encounter gets into its most chaotic state at low boss HP; many groups wipe in the last 10% of the fight due to Decima getting 10 stacks!

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Standing in the Green Arrow is the responsibility of the boss group, while positioning this arrow near the boss group is the Kiter’s job by standing on the opposite side of the boss from them.

As the boss gains stacks of Peal of Discord every time she loses 10% of her HP, the Spread mechanic can overlap with the Green Arrow. nullifies the Spread mechanic entirely, so that is the first line of defense against this nasty combination!

If a situation arises where is not available, players should avoid stacking all five Spreads together if possible while still remaining along the Arrow’s length. If moving out along the Arrow’s length is not possible due to a Fence, stack as much as possible and be prepared to resurrect any downed players after the sequence concludes.

Note: The boss will never do her deadly jumping attacks while the Green Arrow is on the field, so all boss group players can and should run through the boss’s hitbox in order to expeditiously reach this mechanic in time. Another helpful option for reaching a Green Arrow that’s placed far from the boss group is a well-timed Sand Swell.

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Strategy: Static or Clock?

The two current strategies for phases 2 and 3 that the community have adopted are:

• A static positioning strategy where the Arrow baiters never move from their safe position between two conduits at the start of the phase.
  • The benefits of this strategy are a much lower conceptual complexity barrier for the baiters; they can essentially stay AFK for the entire phase if given for the boss’s crowd control abilities.
  • On the other hand, this strategy increases the complexity of the encounter for the boss group who have to collect Sparks, and especially for the Kiter who may place their Sparks from Harmonious Thunder closer to the baiters by mistake OR spawn the Green Arrow in more inconvenient positions.
  • This strategy is also much less forgiving of double and triple-charged conduits as they will make the space available for the arrow baiters to sidestep Sparks extremely small.
• A ‘clock’ strategy (adapted from ideas from the Reddit post here) where both groups rotate up to 90° clockwise whenever Decima consumes stacks of Peal of Harmony. This means most of the time, the group will move after each set of Arrows fire, but groups with lower damage may have to stay still for two sets of Arrows as she didn’t power up any conduits the first time.
  • This slightly increases the overall complexity of the encounter as everyone will have to remember to move, and the Arrow baiters will have to move only when conduits near them power up. In general, this strategy is less effective in groups with lower damage due to this consideration.
  • The clock strategy makes life extremely easy for the Kiter and boss group. The Kiter can simply stand with the rest of the Arrow baiting group for each set. The boss group can stand directly on the opposite side of the boss and will never have to go near the baiters.
  • With the Kiter’s positioning as such, Harmonious Thunder will power up conduits near the baiters as expected (which is normally bad when not changing positions), but after the Arrows the group will rotate out of their way, making Sparks always spawn counterclockwise from them (and never behind them!), ripe for the picking for the boss group after a rotation of their own.