Twilight Drover, Phyrexian Altar, and Heartstone

Prerequisites

• Twilight Drover on the battlefield
• Phyrexian Altar on the battlefield
• Heartstone on the battlefield
• Twilight Drover has at least one +1/+1 counter on it
• available

Steps

1. Activate Twilight Drover by paying and removing a +1/+1 counter from it, creating two 1/1 Spirit creature tokens
2. Activate Phyrexian Altar twice by sacrificing the Spirits, adding
3. When the Spirits die, Twilight Drover triggers twice, putting two +1/+1 counters on itself
4. Repeat

Results

• Infinite +1/+1 counters on Twilight Drover
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers