Dark Heart is an archetype created by user Scorn9 and premiered in the booster pack Resurrected Prominence. The deck is based around Fusion summoning high ATK monsters with extremely powerful effects using "Dark Heart" monsters and, usually, the Opponent's Monsters. The "Dark Heart" Monsters' effects activate when used as fusion material, and have effects that activate when monsters of certain attributes are used as the other fusion material monsters. Shadowsoul Monsters are the Fusion Monsters that require "Dark Heart" monsters as fusion material. Currently, there are only four "Dark Heart" Monsters and 2 "Shadowsoul" Monsters, but more are expected within Scorn9's next booster pack.
Playing Style[]
For "Dark Heart" and "Shadowsoul" decks, fusion summoning is the name of the game. That means heavy use of "Polymerization" and "Fusion Gate", but for the most part, "Super Polymerization" and the generic "Dark Heart" spells and traps. The "Dark Heart" effects work much like the Monarchs: where "Mobius the Frost Monarch" destroys 2 Spell/Trap upon being Tribute Summoned, "Dark Heart Vasi" destroys 3 Spell/Trap when used in a Fusion Summon with a WATER monster as another Fusion Material.
The main weakness found in "Dark Heart" decks is their reliance on fusion summoning and lack of consistent searching after "Sangan" and "Mystic Tomato". Another issue is that every "Dark Heart" monster is of a different type, making "Rivalry of Warlords" an exceedingly dangerous card. In the current meta, "Dark Heart" is just too inconsistent a play style to actually use, though they do work extremely well splashed into other deck-types, the most prominent of those being "Elemental HEROs"