Some bits of information:
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Ardent Flame skillline:

Ultimate - Standard of Might is *the* Ultimate for DK-DDs and the go to Ult for pretty much any boss fight.

Active Skills:

- Molten Whip: is the main spamable for DK-DDs in pretty much any boss fight. This Morph also benefits from the stacking bonus from other Ardent Flame abilities.

- Searing Strike (into Venomous Claw): a very strong DoT that ramps up in damage the longer it ticks (therefore the preferred Morph nowadays

- Fiery Breath: the Morph is dependent on situation; Noxious Breath is for situations where you need a Major Breach source on hand; Engulfing Flames has a 6% damage bonus, but if another DK in group runs this, it doesn't really give any benefit apart from the DoT

- Chains of Devastation: With the 'Scribes of Fate' patch this skill got the Major Berserk buff added to it, which is a good chunk of damage improvement, but it is only 4 seconds long and the fact that you pull yourself towards the boss with this ability it might not be viable to run in some situations.

- Flames of Oblivion: good due to the Major Prophecy and Savagery buff, counts toward the whip stacking, can be used as a spamable when you have multiple targets; a standard skill that you always want on your front bar

Passive Skills:

All of the passives are benefiting a DD so you should pick all of them up.

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Draconic Power skillline:

Ultimate - not used

Active Skills:

- Spiked Armor: not used (Volatile Armor morph maybe used in very niche situations)

- Burning Talons: a very cost intensive skill that hits your sustain a lot, but is more or less a skill you always want in your setup due to the high damage + the high damage sinergie for allies

- Coagulating Blood: In situations where you need a fast heal this is a strong option

- Protective Scale: not used on DD

- Deep Breath: good AoE damage + a heal dependent on afflicted damage; finds its use in some situations

Passive Skills:

All of the passives are benefiting your survival, so they are worth picking up

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Earthen Heart skillline:

Ultimate - not really used (maybe Corrosive Armor in niche situations)

Active Skills:

- Stone Giant: can be used on a DD for the stagger buff if not maintained by a Tank

- Igneous Weapons: can be used by a DD to keep up the Major Brutality and Sorcery buff if not maintained by a Tank

- Obsidian Shield: not used

- Petrify: not used

- Eruption: strong AoE skill pretty much always used on a DD

Passive Skills:

All of the passives are benefiting you (and your group)

- Battle Roar: the amount of point you spent in this passive depend on what sets you run, if you use Bahsei or Coral Riptide you only want 1 point in it, as it otherwise would bring your recourse pools up to high (making you loose damage); with any other set you can put in 2 points to benefit fully from the recourse gain

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If you click through the other different skilllines I have picked up skills that can be used dependent on weapons used and situations. (skills which haven't been morphed mean, that both morphs can be used dependent on situation/sustain)

There is also a sort of generic skill loadout if you are a full parse DD (that is not using Tzogvin or other sets that give Minor Force).

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When it comes to rotation it is always better when you can do a dynamic rotation and keep up skills this way; If you use Talons in your rotation the ideal way to use it, is: Talons - 3*skills - Talons - 3*skills - .....

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Equipt blue CP is also a general guidance and can vary depending on situation and skills used.