Twilight Shepherd + Phyrexian Altar + Sneak Attack

Twilight Shepherd

Phyrexian Altar

Sneak Attack

How it works

1. Sacrifice Twilight Shepherd to Phyrexian Altar to add .
2. Twilight Shepherd's persist triggers, returning it to the battlefield with a -1/-1 counter.
3. Sacrifice Twilight Shepherd to Phyrexian Altar to add 1.
4. Twilight Shepherd triggers, returning it from your graveyard to your hand.
5. Pay to Sneak Attack to put Twilight Shepherd onto the battlefield from your hand.
6. Repeat.