Most of your characters have good stats for banishing their rivals in challenges, and if they don't there are easy ways to pump them up, either with a song, or as the side effect of a song
Cyclonic Rift Cyclonic Rift is a one-sided board reset that scales perfectly in multiplayer and is one of the best blue cards MTG has produced specifically to end Commander games decisively
I like the base 3/3 and generic to activate the Curator, and I like the +1/+1 counter and lifegain on the Scavenging Ooze, so if you have slots for green cards, why not both
The Do-Over Project is still ongoing because we keep getting saucy new sets with creative and colorful commanders to build new decks with
The downside is that you cant touch Progenitus either, but does that really matter when you can shut down the game in a swing or two
Each player loses life equal to the number of creatures they controlled that were destroyed this way