I was kind of surprised he didn't have anything. The fight took awhile but it's pretty hard to die unless you just decide to sit and DPS for way longer than is reasonable.
Edit: I was also surprised to find that you can leash all the shadows and not even kill them. Though, I killed them all on the actual successful kill attempt.
Yeah, you can just run from them for 30s and they despawn. Pretty dumb.
Congrats btw