Activate Wall of Roots by putting two -0/-1 counters on it (due to Lae'zel), adding .
Activate Tayam by paying 3 and removing three counters from creatures you control.
In response to Tayam's ability, activate Ashnod's Altar by sacrificing Wall of Roots, adding .
Resolve Tayam's ability, milling yourself three cards and returning Wall of Roots from your graveyard to the battlefield with two vigilance counters on it due to Tayam and Lae'zel.
Repeat.
This clever loop relies on Lae'zel, Vlaakith's Champion to supercharge your resource generation, ensuring that Wall of Roots receives an extra -0/-1 counter when activated and returns with extra vigilance counters from Tayam, Luminous Enigma. By feeding Wall of Roots to Ashnod's Altar, you generate the colorless mana needed to pay for Tayam's resurrection ability while fueling a continuous cycle of self-milling and creature returns. Because Tayam, Luminous Enigma continually pulls the wall right back out of the graveyard to replenish your counter supply, the engine sustains itself indefinitely for a loop of sacrifice and enters-the-battlefield triggers.