In this implementation using triggers, ideally you'd also also be able to select a character for the trigger to proc on, even if they're currently not visible or targetable from your position. I.e., "I only want to counterspell/attack this enemy. If they remain behind cover, then I guess I can't do anything. But if they move from cover into my sight...gotcha!"
Yep, sounds good! I’d love that in situations with invisible enemies. The moment they pop back into view, I want to nail them with Scorching Ray (if I’ve line of sight, of course). That could mean wasting turns waiting for Invisibility to end, but that’s what happens anyway when the last enemy drinks an Invis potion and you’re left twiddling your thumbs while the game prolongs the inevitable.
