Discussion about Dungeon (Dark Elves).

They focus their attacks on the Riders.

I haven't seen that. They just kill them without focusing.

if they survive after the counterattack...

Are you kidding? Who's going to counterattack? They one-shot them. And there's usually no counterattack. Or they just attacked the wrong target.

By the way, does vampirism work on their special unblockable attack?

I don't know about that – I haven't had a chance to check. I didn't have Riders by the time I cast Vampirism. I cast it on the Reds, though. But they didn't last long either. The most effective option is Phoenix.