According to the RC's explanation for the ban "tapping out at a healthy life total against an opponent with nothing but any 5-color Commander in play shouldn't cause you to lose the game, unless you have signed up for that kind of experience." If I were to design a 'fair' version of Coalition Victory, it would require every color and every land to be accounted for by a different card
(A creature with shadow can block or be blocked by only creatures with shadow.) : Add
While I'm not sure how scared I am of a Turn 3 Batterskull in a format where you die to Storm on Turn 3 or get Primeval Titaned on Turn 4, probably the biggest risk is that having a big uptick in play from Batterskull would push aggressive creature decks (which really struggle with Batterskull) out of the format and potentially throw the currently diverse format out of whack
Longer-term, itll depend on how the Urza-based Whir Prison decks end up performing
If you can play Smothering Tithe, youre probably going to pick that first, but I think Id hedge on Monologue Tax over Tempting Contract
Koma offers something different compared to other Simic Legendaries as it cares about interacting in combat, rather than unloading your hand with lands to draw more cards