First, you need to pick a legendary creature, vehicle, spacecraft, or planeswalker as your commander, which is placed in the command zone at the start of the game
Use cards like Enlarge to get a single cat's power extremely high, then use your commander to double their stats and give them trample
Use Master of Death as a creature for continuous discard with Existence and it can return to your hand from graveyard at your upkeep to keep rolling with Existence or other effects
Mega Brave & Mega Symphonia Release date: TBC As reported by Pokebeach, new trademarks for Mega Brave and Mega Symphonia by Pokmon match the same terms as trademarks used for previous set names
Decks that dont care about those elements have much better options
Where it gets truly strong, though, is playing those creatures that get arbitrarily large think Malignus, or Taurean Mauler and following up with instant speed Burn spells