At the beginning of your upkeep, Ravos triggers, returning Myr Battlesphere from your graveyard to your hand.
Cast Myr Battlesphere by paying {7}.
When Myr Battlesphere enters the battlefield, it triggers, creating four 1/1 Myr artifact creature tokens.
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.
Repeat each turn.

Infinite turns

Ravos, Soultender

Time Sieve

Myr Battlesphere

At the beginning of your upkeep, Ravos triggers, causing you to return a creature card from your graveyard to your hand.
Activate Timestream Navigator by paying {2}{U}{U}, tapping it, and putting it from the battlefield onto the bottom of your library, causing you to take an extra turn after this one.
Activate Fauna Shaman by paying {G}, tapping it and discarding a creature card, searching your library for Timestream Navigator and putting it into your hand.
Cast Timestream Navigator by paying {1}{U}.
Repeat each turn.

Combos with "Ravos, Soultender"