Lazav, the Multifarious + Lesser Masticore + Ashnod's Altar + Nardole, Resourceful Cyborg

Lazav, the Multifarious

Lesser Masticore

Ashnod's Altar

Nardole, Resourceful Cyborg

How it works

1. Activate Lazav by paying 2, choosing to have it become a copy of Lesser Masticore if it doesn't have a -1/-1 counter on it, or Nardole otherwise.
2. Activate Ashnod's Altar by sacrificing Lazav, adding CC.
3. When Lazav dies, if it was a copy of Lesser Masticore, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
4. Otherwise, Lazav's undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
5. When Lazav enters the battlefield, it triggers, causing you to surveil 1.
6. Repeat.

This clever loop transforms Lazav, the Multifarious into an endlessly recycling engine by leveraging the classic interaction between persist and undying. Because Lazav retains its copy ability and surveil trigger while shifting shapes, you can adapt to its current counter state: when it wears a -1/-1 counter, you pay {2} to become a copy of Nardole, Resourceful Cyborg so its undying ability triggers upon sacrifice, and when it wears a +1/+1 counter, you become a copy of Lesser Masticore so its persist ability takes over. Ashnod's Altar acts as the sacrificial outlet that feeds this cycle while conveniently generating mana, letting you continually bounce Lazav back and forth to rack up infinite death triggers, enter-the-battlefield triggers, and surveil activations.