Proliferate is already a mechanic that's heavily associated with Phyrexia, and with saga counters, shield counters, stun counters, and poison counters all in Standard right now, the groundwork has definitely been laid for it to make a comeback
Really enjoyed our discussion about this and I'm really curious to see if/what kinda spin you would put on it!
If you are playing against 3 other folks in a pod of four players, then you are being outdrawn 3:1 every turn that passes
Take a look and share your opinions on them in the comments
your Regrowth costs 1, and anything that costs 1 or less becomes free or even generates mana
However, when the player can guarantee they go first, Summon Limit more often than not can completely shut down the opponent's turn, which can then guarantee a win on the next turn