Scuttling Sliver + Trazyn the Infinite + Unnatural Selection + Mana Vault

Scuttling Sliver

Trazyn the Infinite

Unnatural Selection

Mana Vault

How it works

1. Activate Unnatural Selection by paying 1, causing Trazyn to become a Sliver until end of turn.
2. Activate Trazyn using Mana Vault's ability by tapping it, adding CCC.
3. Activate Trazyn by paying 2, untapping it.
4. Repeat from step 2.

This clever loop turns the graveyard into an engine by letting Trazyn the Infinite inherit the explosive mana-producing activated ability of Mana Vault. Since Mana Vault doesn't have a tap symbol in its actual activation cost restriction—it just taps as part of producing three colorless mana—Trazyn can freely tap for mana using that stolen capability. To keep the magic going, Unnatural Selection temporarily turns Trazyn into a Sliver, granting him Scuttling Sliver's activated untap ability so he can spend a portion of his newly generated mana to untap himself and repeat the process indefinitely.