Xantcha, Sleeper Agent Combos
Cadaverous Bloom + Zirda, the Dawnwaker + Xantcha, Sleeper Agent
Xantcha, Sleeper Agent + Mind over Matter + Basalt Monolith
Xantcha, Sleeper Agent + Mind over Matter + Chromatic Orrery
Combo result
Infinite lifeloss for target opponent. Infinite draw triggers. Near-infinite colorless mana. Near-infinite card draw. Near-infinite looting. Near-infinite self-discard triggers. Near-infinite untap of permanents you control.
Prerequisites
All permanents on the battlefield. Xantcha on the battlefield under an opponent's control.