Presumably, your opponent is going to play creatures at some point
Lumra, Bellow of the Woods These days, 6-mana creatures need a lot of impact in Commander
Heck, even if grabs whatever Overrun effect on a Creature you've got near the top in your tokens deck, or pulls another Power buff in your Elves Kindred deck, it'll almost certainly do excellent work
This, and Peters aptitude for science and invention (like his web-slingers) is very blue
She also lets you run your favorite Planeswalkers like Serra or any of the Elspeths in a shell that is already geared toward protecting a Planeswalker in the command zone
I don't like that, but she's pretty flexible, the most common things she's with are things that play with time counters, and then One with the Multiverse and Ovika, Enigma Goliath