Gardevoir ex can attach as many Psychic Energy from your discard pile as you like during each turn with its Psychic Embrace Ability, and that allows you to power up some strong attackers
Split second doesn't stop triggered abilities from triggering, such as that of Chalice of the Void
Against Hammer for example, destroying Shadowspear is often a game-winning move
Unless the agro player can kill this on sight it ends games quickly, even if it dies before it kills them it has still usually had such an impact on the life totals that the game is out of reach
Infernal Sovereign Granted, its a hefty mana cost, but the potential return value you get is quite high
Therefore, if you create too complex rule interactions, dense UIs, or cards with multiple steps of interaction, this can overwhelm mobile users (while working perfectly fine on desktop)