Say an enemy Durant w/Traunt uses Entrainment on my beloved Braviary, and I have Braviary use Fly. Will Braviary be stuck up in the air to loaf around? Will he use Fly and then loaf around when he comes back down? Will it fail?
Your Braviary would loaf around in the air, since Fly is a move that charges on the first turn. Truant would cancel the attack. Also, Slaking can learn Solarbeam (see here), which works in the same way.