But I'm burying the lede the real story here is LAND TAX
I think The Eldest Reborn is one of the most powerful effects in the Standard format and was a sideboard sleeper for a very long time in the previous Standard format
If we preferred black instead, we might consider a Tezzeret the Schemer style of deck (obviously still using Karn), as Tezzeret is great for ramping into Karns Temporal Sundering and synergizes well with a lot of the same cards we might be interested in because of Karn
In a Two-Headed Giant game, Providence causes the teams life total to become 26, but only you actually gain or lose life
Bennie Bracks, Zoologist is a great way for token decks to see at least an extra card each turn with a minimal mana investment, thanks to convoke often making this close to, if not entirely free
Regardless of this, Limit Break goes really well with Fallout 's Scrappy Survivors deck, which features the same color identity and the same overall themes as Limit Break