I met 3 of them but it was late game when i was already fully upgraded and I didn't want to fight them.
Instead fighting, I took them to plains to make some mess.
The first one took down half of a small fuling village before he was killed.
The second one wasn't that lucky... I introduced him with a 2 star Berserker. He didn't stand any chances.
The third one also didn't have much luck. He barely made it to fuling village because there were a lot of loxes and deatsquitoes on the way.