Circuit Mender + Mortuary + Ashnod's Altar + Cloud Key

Circuit Mender

Mortuary

Ashnod's Altar

Cloud Key

How it works

1. Activate Ashnod's Altar by sacrificing Circuit Mender, adding CC.
2. When Circuit Mender dies, its second ability and Mortuary trigger.
3. Resolve the Mortuary trigger, putting Circuit Mender on top of your library from your graveyard.
4. Resolve the Circuit Mender trigger, causing you to draw Circuit Mender.
5. Cast Circuit Mender by paying 2.
6. When Circuit Mender enters the battlefield, its first ability triggers, causing you to gain two life.
7. Repeat.