Sporoloth Ancient + Tainted Observer + Ashnod's Altar + Doubling Season

Prerequisites

• You control a creature with at least three spore counters on it.

Steps

1. 1Activate a creature you control by removing two spore counters from it, creating two 1/1 Saproling creature tokens.
2. 2The Saprolings enter the battlefield, triggering Tainted Observer twice.
3. 3Holding priority, activate Ashnod's Altar by sacrificing a Saproling, adding .
4. 4Resolve the first Tainted Observer trigger, causing you to pay to put two spore counters on any creature you control.
5. 5Resolve the second Tainted Observer trigger, choosing not to pay.
6. 6Repeat.

Effects

• Infinite colorless mana
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite creature tokens
• Infinite death triggers
• Infinite proliferate