I use Psyduck's "Overthink" attack to cause flips to be treated as Tails whenever your opponent flips a coin on the next turn. But if my opponent plays Will, which allows the player to choose the outcome of the first coin flip required for an attack, does my opponent get to choose heads for their first coin flip or is it still tails due to "Overthink"?
Overthink will cause the flip to be treated Tails regardless of Will, since Overthink is in effect whenever your opponent flips.
OverthinkWill