Can I use Mega Charizard Y ex's "Explosion Y" attack if I have two Basic Fire Energy and a Counter Gain tool attached to it if I'm behind on Prizes?
Yes, even though you are only discarding two Energy you can use the attack.
Source: Ascending Heroes FAQ; TPCi Rules Team (2026-01-22)

Relevant cards

Note: All applicable cards may not be listed below.
ME25_22
ME25_22
SV8_169
SV8_169