If the card has X in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost
Team Rocket's Mewtwo ex (Special Illustration Rare) Card 231/182 From Scarlet & Violet: Destined Rivals The Pokmon TCG: Scarlet & Violet Destined Rivals set centers around Team Rocket and therefore has many impressive cards for Team Rocket and their Pokmon companions
At the beginning of your upkeep, you may put a creature card exiled with Chaos Shrines Black Crystal onto the battlefield under your control with a finality counter on it
Considering a standard casual table (4 players), you may get one out of three different buffs whenever it is your upkeep
Notable about Rootha is that she cares about the mana value, not the mana cost unlike some cards, which means that spells that reduce their cost are fine here, and that she only rewards one spell on your turn, so to maximize her you want to lean into those elements