I was hoping someone could help me out with a rules question. If a hero with multiple wounds is hit with Beguile, he cannot deal damage as a defender til the end of the round. If the hero survive melee that round, could he then strike back still in the same round?

No.

Beguile isn't removed until after the melee phase is finished, so the target isn't able to respond.

That's what I thought, but a friend of mine argued that he could. Thanks!