Or in Purphoros, Bronze-Blooded, a 5cmc commander full of expensive creatures, a 3cmc ramp card that taps for 2+ mana like Worn Powerstone is ideal because it lets you cast your commander two(!) turns early and start sneaking out your haymakers
Sure, you have to give up four damage to get Refraction Elemental, but it should more than make up for this in just one turn on the battlefield, which should make defeating the battle worthwhile pretty often
+1: Create an X/X green Phyrexian Horror creature token, where X is Nissa's loyalty
Sakiko, Mother of Summer Mogis, God of Slaughter Mogis taught Rakdos everything he knows
Thassa's Oracle I bet designers never imagined Thassa's Oracle would be used the way it is now as a cEDH win condition
Claw Slash is a decent 80-damage move that can be used after attaching 3 of any kind of energy, making this an awesome card for dual-type decks