SR Super Rare Marincess Wonder Heart X WATER Link 4 [ CyberseLinkEffect ] ATK 2400 DEF - 2+ WATER monsters Once per battle, during damage calculation, if this card battles a monster (Quick Effect): You can Special Summon 1 of your "Marincess" Monster Cards equipped to this card, also this card cannot be destroyed by that battle, and you take no battle damage from that battle
In grindy Commander pods, it turns your mana base into a resource you can reuse over and over
This isn't a one-off piece of lore that has been retconned either - Ruby, Diamond and Pearl, Heartgold and Soulsilver, Black and White, Black and White 2, X and Y, and Alpha Ruby and Omega Sapphire's Pokedex entries for the poor thing all make reference to this
You may have creatures you control with no abilities assign their combat damage as though they weren't blocked
3 Revavroom
C Common Warning Point X TRAP When a monster(s) is Summoned: This turn, that face-up monster(s) cannot attack, its effects are negated, also it cannot be used as material for a Fusion, Synchro, Xyz, or Link Summon