Nim Deathmantle triggers, causing you to pay ({4} magic symbol) to return Dryad Arbor from your graveyard to the battlefield, and attaching
Nim Deathmantle to it.
When
Ashaya enters the battlefield,
Down in the Valley triggers, creating a creature token.
Activate
Ashnod's Altar by sacrificing the creature token, adding ({C} magic symbol) ({C} magic symbol) .
Repeat.
If you control a nontoken creature that has haste, you may instead sacrifice it, and then tap it each iteration to get infinite green mana and colorless mana.
Results
Infinite creature ETB.
Infinite creature LTB.
Infinite colorless mana.
Infinite death triggers.
Infinite green mana.
Infinite landfall triggers.
Infinite creature sacrifice triggers.
Metadata
Bracket tag
ExhibitionBracket 1+
For any deck
1
2
3
4
5
1 · Exhibition5 · cEDH
Bracket tags are estimated from the cards and results of each combo, as a guideline rather than a strict classification.