Hearthpwn

Let them dirty rat and deathlord out my free 8/8s. I'll win on tempo as I'm drawing a ton more.

This may actually become a thing. 

 Empty board. 

Play this. 

Summons Malygos, 2 moonkins, velen, 2 spelleavers or cosmic anomalys, + 1 of the remaining. 

Total of +15 spell damage before velen. 

Play smite with your 1 remaining mana. 

17 damage, plus the velen, so...34 damage. 

You have a 34 damage OTK from an entirely empty board from 2 cards in hand, assuming your 2 major cards (Maly, velen) aren't already drawn, and the rest of your deck is still stacked with +2 damage minions. It's worth noting that you could probbaly achieve a similar effect if one of the minions is a knife juggler. You could even pull off the combo if one or even TWO of the minions is only +1 spell damage (32 or 30 damage total, instead of 34). 

Just came to say that reveal video is astonishing.

No, it isn't. Recruit is different from swap. Especially for warlock, which can often run into fatigue due to all the card draw. 

Swap implies that this 5/5 does it's job, gets killed, then goes BACK in the deck, leaving you without card the lower deck count that recruiting would yield. 

Additionally, recruit an 8-cost minion can fail if your deck ran out of 8-cost minions (but you still have let's say voidlord or doomguards you don't want to hard-cast, 2 of the most popular cards in warlock. And of course mountain giant. This can bring out any / all of them, and it lends itself far better to "value" deck archetypes where you produce copies and shuffle in multiple versions of this, creating in essence multiple 5/5 versions of wax rager. 

There are a lot of possibilities here that the 7-cost 3/3 just doesn't have.

He probably read it as 

"Deathrattle: minions you play..."
instead of
"Deathrattle minions you play..."

I did too, the first time. Colons ain't just for poopin', ya know.

Devolve. Can't believe I haven't read it before. [Best part? You'll read it in his voice]