When using Imakuni?'s Doduo's "Harmonize" attack, what happens if I forget the words to the song?
As soon as you stop singing, the damage is done to the current Defending Pokemon.
Source: Evolutions FAQ (2016-11-03), TPCi Rules Team (2016-11-03)

Relevant cards

Note: All applicable cards may not be listed below.
XY12_112