Activate Prize Pig by tapping it, adding {W}.
Activate Peace of Mind by paying {W} and discarding Cleaving Reaper, causing you to gain three life.
Prize Pig triggers, putting three ribbon counters on it, then removing all ribbon counters on it and untapping it.
Activate Cleaving Reaper by paying three life, returning it from your graveyard to your hand.
Repeat.

Infinite lifegain triggers

Infinite self-discard triggers

Prize Pig

Peace of Mind

Cleaving Reaper

Pay 3 life to return Cleaving Reaper from your graveyard to your hand.
Tormod triggers, creating a 1/1 Bat token.
Sacrifice the Bat token to Phyrexian Altar for {W}.
Pay {W} and discard Cleaving Reaper to gain 3 life.
Repeat.

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Desecrated Tomb

Phyrexian Altar

Pay 3 life to return Cleaving Reaper from your graveyard to your hand.
Tormod triggers, creating a tapped 2/2 Zombie token.
Sacrifice the Zombie token to Phyrexian Altar for {W}.
Pay {W} and discard Cleaving Reaper to gain 3 life.
Repeat.

Tormod, the Desecrator

Combos with "Peace of Mind"