The Geass collab brought with it a very silly game mode where you can potentially score a 5x multiplier on your hand score. This turns something pretty basic into a game-ending one-shot kill.
Probably the best thing Mahjong Soul does is these silly non-competitive variants for events. I don't play it much because the grind is atrocious, but no question that Soul re-energized online mahjong by just taking oppressive ranked pressure off people and letting them just have fun playing mahjong, nya.
