Unstoppable Slasher, Hex Parasite, Ashnod's Altar, and Vein Ripper

Prerequisites

• Unstoppable Slasher on the battlefield
• Hex Parasite on the battlefield
• Ashnod's Altar on the battlefield
• Vein Ripper on the battlefield
• Unstoppable Slasher does not have a counter on it

Steps

1. Activate Ashnod's Altar by sacrificing Unstoppable Slasher, adding
2. When Unstoppable Slasher dies, its second ability and Vein Ripper trigger
3. Resolve the Unstoppable Slasher trigger, returning itself from your graveyard to the battlefield with two stun counters on it
4. Resolve the Vein Ripper trigger, causing you to gain 2 life and an opponent to lose 2 life
5. Activate Hex Parasite by paying and 2 life, removing both stun counters from Unstoppable Slasher and giving Hex Parasite +2/+0 until end of turn
6. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite lifegain triggers
• Infinite lifeloss
• Infinitely powerful Hex Parasite until end of turn