Muldrotha, the Gravetide + Sidisi, Undead Vizier + Beacon of Tomorrows

Muldrotha, the Gravetide

Sidisi, Undead Vizier

Beacon of Tomorrows

How it works

1. Cast Sidisi from your graveyard by paying 3.
2. When Sidisi enters the battlefield, its exploit ability triggers, causing you to sacrifice Sidisi.
3. Sidisi's second ability triggers, causing you to search your library for Beacon of Tomorrows and put it into your hand.
4. Cast Beacon of Tomorrows by paying 6, causing you to take an extra turn after this one and shuffle Beacon of Tomorrows into your library.
5. Repeat each turn.