Eve of the Apocalypse: Twilight

Better idea: They automatically come with every tenth wave from a top-tier town hall.

That's why it needs to be a random thing. Or one with every wave.

Hmmm. Yeah, it might be better if sometimes one wave had a captain and the other teams' didn't. Then you'd have to make sure to defend that lane personally, since the creeps would be stronger...

I don't know how well this would work, but what if one spawn in every wave was given an Aura that boosted the damage of all nearby allies by... Let's say ten. It would add a bit more strategy for heroes, since you'd need to take them down quickly so that your spawns could steamroller them, and you'd...