Time Sieve + Myr Battlesphere + Karador, Ghost Chieftain

Time Sieve

Myr Battlesphere

Karador, Ghost Chieftain

How it works

1. Cast Myr Battlesphere from your graveyard by paying 7.
2. When Myr Battlesphere enters the battlefield, it triggers, creating four 1/1 Myr creature tokens.
3. Activate Time Sieve by tapping it, sacrificing Myr Battlesphere and sacrificing the four Myr tokens, causing you to take an extra turn after this one.
4. Repeat each turn.