What the heck? (Monk's Path)

Okay, for this mission, you have to kill Eater of Souls, who's apparently a boss Jade Scarab, who in Diviner's Ascent.

Okay, I go to where he is, and approach him.....................

And then he vanishes. Is this supposed to happen. I went up to where he was exactly, and about 10 or 15 Jade Scarabs just came from the ground.

Is this supposed to happen? Am I supposed to kill all the Scarabs (because there seems to be a never-ending supply of them)?

Help!

Yeah he pops into the ground and hides until you kill a bunch of scarabs first.

Thanks! I figured as much, and I ended up killing him before I saw your reply.........but thank you, kind professor.