Tough call if youre Rakdos, but in my Jan Jansen, Chaos Crafter deck, we are five by five
We usually hold him until weve got a recursion outlet online, so the tokens actually start flowing instead of trickling
Yawgmoth, Thran Physician [Sacrifice Engine, Removal & Card Draw] Yawgmoth, Thran Physician turns creatures into cards, removal, and combo fuel
But discarding two cards to draw four over two turns at instant speed seems really strong, and because you aren't spending two cards to do so but just one, this is card advantage unlike most of these effects, as you are our three cards (discard two, and the Revelation) to draw four, which is good math for a non-drawing color like Red
That story still makes me laugh