Carl and Princess Donut enter the Mock Battle Arena to practice deck combat before the upcoming assault date. Donut chooses an elaborate colosseum environment that includes a roaring crowd of Nebular cultists, and Carl warns her about environmental hazards even though the generated mobs can’t directly harm them.

When combat starts, Donut panics because her four drawn cards float in front of her face and block her vision. Carl instructs Donut to adjust the card display and reminds her about the discard rule (one discard every thirty seconds, with a new card appearing ten seconds later). While Donut fumbles with the interface, Mongo charges the enemy and instantly kills a small purple creature, ending the match so quickly that Carl feels the gold cost was wasted.

They run the arena again on easy difficulty, but this time Carl makes Donut remove the loud crowd by switching to an “abandoned arena” variant. As they talk about Miss Beatrice’s strange habit of crying while watching children’s shows, Carl focuses on testing practical deck behavior: Donut draws a hand without the totem, so Carl tells her to discard the Combo card immediately to avoid being vulnerable and to cycle the hand.

When the Monk Seal totem card appears, Donut summons Geraldo, who arrives with exaggerated kung-fu sound effects and a visible timer/health bar. Donut successfully applies utility cards to Geraldo, using Stout to buff him and a Time Extend to add sixty seconds, but she cannot apply a third utility card. The system message reveals the reason: uncommon totems can only hold two utility cards.

The generated opponent turns out to be a Squonk, a miserable legendary creature that doesn’t fight. It cries, rolls over, and dissolves into water on its own, ending the combat. Carl concludes that easy mode may be too uninformative for meaningful practice and suggests they may be better off trying medium difficulty.