The Ark Conflict

Unstable 7
When The Ark Conflict enters the battlefield, create a 1/1 Sentinel Aggressor artifact creature token
When the Ark Conflict leaves the battlefield, choose two:
- create 3 1/1 Sentinel Aggressor artifact creature tokens
- create a 4/4 Sentinel Enforcer artifact creature token
- Search your library for a Halo Ring card and put it into your hand