Don't have him myself, though you can fuse him from rare heroes and there's a progress mission requiring you to do that.
Really nice 4* chicken.
Or maybe useful up to mid SIlver? Or your best Vault Keeper?
It doesn't matter what we think of him, it is more important can he help you. He may be your best bet for the next weeks or so or may be your worst investment. Most likely he is your first purple, so may worth some investment after all, but how can someone knows for sure?
But since you ask what we think of him - well, I don't like him. Didn't like him from the very beginning, from the moment "One Man Army" Relic Keeper in arena wipe the floor with my 4 arena team. :) Didn't like him now too because i see him how useless is in middle/late game.
Good campaign farmer, although slow.
Excellent in arena through silver into gold 1 and 2, he basically counters all the kael/apoth teams you see. A lot of survivability for an attack epic. My first foray into gold 4 was with him.
Okay for some pre late game dungeons to help clear waves. Kinda good at killing the respawning minions on ice golem.
Not endgame viable. He was my first 60. I only use him faction wars now.