Heart

The "Heart" archetype is a loose collection of boss monsters and support cards shared across three distinct strategies — Kashtira, Mannadium, and Tearlaments — each of which requires several moving pieces before its respective "Heart" card becomes live. None of the three can be dropped on the first move from a cold hand; they all demand prior setup, whether that means climbing through Level 7 Xyz materials, chaining Synchro Tuners, or milling Aqua monsters through the graveyard.

Kashtira Arise-Heart is the most self-contained of the three, attaching banished cards as Xyz materials automatically and then spending three of them to banish a card on the field face-down, where it is effectively unreachable. Its passive replacement of graveyard sends with banishment disrupts every strategy that relies on the graveyard as a resource. Mannadium Prime-Heart rewards stacking multiple Tuners during its Synchro Summon, gaining one attack per Tuner used while remaining untargetable by opponent's effects, and Mannadium Breakheart provides graveyard recursion and battle protection to keep the engine going across turns. Tearlaments Kaleido-Heart clears opposing cards by shuffling them back into the deck each time it is summoned or an Aqua monster is sent to the graveyard, and it recovers itself if destroyed by card effect, refuelling the mill engine in the process.

Tearlaments Heartbeat ties into this loop neatly, bouncing spells and traps while feeding the graveyard and recovering Tearlaments Traps when milled, ensuring that even disrupted turns generate advantage toward the next summon of Kaleido-Heart.