Origins Main Set OGN-123/298 epic Official FAQ
Unchecked Power
Card Text & Abilities
Exhaust all friendly units, then deal 12 to ALL units at battlefields.
Official Rules FAQ & Clarifications
1 Official FAQ Q:
What about other units that die at the same time as Wraith of Echoes, such as to a mass damage spell like Unchecked Power?
A:
No. Units that die also don’t “see” anything else that dies at the same time they do.
Source: Official FAQ: Origins FAQ →