Cross posting from the Evoker class forums (Breath of Eons Doesn't Trigger for Early Kills).
Breath of Eons is a talent/spell for Augmentation Evokers which replaces Deep Breath and “accumulate[s] 21% of damage dealt by your allies affected by Ebon Might, then critically strikes for that amount as Arcane damage”. However, if a creature under the Breath of Eons effect dies early it doesn’t detonate for any amount, it just dies and you get no extra damage from the breath debuff. This seems like an oversight or a bug - enemies which die before the breath debuff expires should still trigger damage for whatever they’ve accumulated. This would be consistent with a similar ability Arcane Mages have, Touch of the Magi.