Seems rather good (and of course I only play wild so can only speak for that mode.)
But mech’s like M whelp, Sneed’s old shredder, spider bomb for example could all do well with this. (as long as you aktivaste this deathrattle directly as you play it.

I did it last year only for fun on my own wifi for only myself in a private local gathering. Could open all the packs early without any issue.

Welcome into the wild my friend.
This is going to ba a hazel to play against.

I won with a deck that only had legendary minions in it 😀

Sounds like a good idea 😀

Rafaam is original to Hearthstone. Calling himself “the supreme archaeologist”, the ethereal travels different worlds searching for powerful artifacts. He is known for his possession of three artifacts in particular – the Lantern of Power, the Mirror of Doom, and the Timepiece of Horror.[2]

From Wowpedia:

Treading the chaotic spaces between worlds, the ethereals are astral travelers who dwell within the Twisting Nether. They are known to be collectors and traders of arcane items and artifacts. Now drawn to Outland, many ethereals are seeking to track down its treasures and steal them back into the Twisting Nether. They are liars and scoundrels who will stop at nothing to pursue their mysterious aims. The ethereals have no care at all for the Burning Crusade. They would even play both sides of the conflict against each other if doing so would serve to further their own goals.

Is from this https://hearthstone.gamepedia.com/Arch-Thief_Rafaam