Arcane Adaptation + Fain, the Broker + Thornbite Staff + Xathrid Necromancer

UB identity

Commander legal

The 4 combo pieces

• Arcane Adaptation
• Fain, the Broker
• Thornbite Staff
• Xathrid Necromancer

What must be in place

You control at least one additional creature.
Thornbite Staff attached to Fain.
Fain does not have summoning sickness.
"Human" chosen with Arcane Adaptation.

How to execute it

1. Activate Fain's first ability by tapping it and sacrificing a creature.
2. When the creature dies, Xathrid Necromancer and Fain trigger.
3. Resolve the Xathrid Necromancer trigger, creating a 2/2 Zombie creature token.
4. Resolve the Fain trigger, untapping it.
5. Resolve the Fain ability from step 1, putting two +1/+1 counters on a creature you control.
6. Repeat.

What the combo produces

• Infinite +1/+1 counters on creatures you control
• Infinite creature LTB
• Infinite death triggers
• Infinite ETB
• Infinite sacrifice triggers