Karn, the Great Creator + Doubling Cube + Umbral Mantle

Prerequisites

• Doubling Cube does not have summoning sickness.

Steps

1. 1Activate Karn's first loyalty ability by putting a loyalty counter on it, causing Doubling Cube to become an artifact creature until end of turn.
2. 2Activate Umbral Mantle's equip ability by paying , attaching it to Doubling Cube.
3. 3Float at least in your mana pool.
4. 4Activate Doubling Cube by paying and tapping it, adding at least .
5. 5Activate Doubling Cube by paying and untapping it, giving it +2/+2 until end of turn.
6. 6Repeat from step 4.

Effects

• Infinite mana creatures you control can produce
• Infinite mana permanents you control can produce
• Infinite untap of creatures you control
• Infinitely large creature until end of turn