Ageless Entity, Animation Module, Ajani's Welcome, and Ashnod's Altar

Prerequisites

• Ageless Entity on the battlefield
• Animation Module on the battlefield
• Ajani's Welcome on the battlefield
• Ashnod's Altar on the battlefield
• You have a way to cause a creature to enter the battlefield under your control

Steps

1. Cause a creature to enter the battlefield under your control
2. Ajani's Welcome triggers, causing you to gain 1 life
3. Ageless Entity triggers, putting a +1/+1 counter on itself
4. Animation Module triggers, causing you to pay to create a 1/1 Servo artifact creature token
5. The Servo enters the battlefield, triggering Ajani's Welcome
6. Holding priority, activate Ashnod's Altar by sacrificing the Servo, adding
7. Resolve the Ajani's Welcome trigger, causing you to gain 1 life
8. Repeat from step 3

Results

• Infinite +1/+1 counters on Ageless Entity
• Infinite colorless mana
• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite lifegain
• Infinite lifegain triggers
• Infinite LTB
• Infinite sacrifice triggers