A 4/4 Vigilance for four mana is at least playable… sort of. And there’s quite a few knights available. I thought they were supposed to be rarer than soldiers?
Aryel, Knight of Windgrace
Legendary Creature – Human Knight
2W, T: Create a 2/2 white Knight creature token with vigilance.
B, T, Tap X untapped Knights you control: Destroy target creature with power X or less.
There’s an excellent monogreen Nissa available as well, but why not use blue? Actually, I’d rather use a monocolored deck in this particular environment, but I do have a fondness for Simic. Maybe we’ll get back to the other options later on. There’s Rashmi, Eternities Crafter as well.
As you have probably heard, since you’re here, WotC announced a new format today. It’s known as Brawl. If you didn’t hear about, you can find it here. Basically 60 card Commander with Standard legal cards, 30 starting life and some rules they apparently haven’t really thought through on when the commander goes to the Command Zone.