The Tenth Doctor + Mana Echoes + Venture Forth + Hermes, Overseer of Elpis

The Tenth Doctor

Mana Echoes

Venture Forth

Hermes, Overseer of Elpis

How it works

1. Activate The Tenth Doctor by paying 7, removing all time counters from Venture Forth.
2. Venture Forth triggers, causing you to cast it from exile without paying its mana cost.
3. Hermes triggers, creating a creature token.
4. When the creature token enters, Mana Echoes triggers, adding C for each creature you control that shares a creature type with the token.
5. Resolve Venture Forth.
6. Repeat.

This loop begins with The Tenth Doctor's massive time-travel activation, which instantly strips the final counters off exiled copies of Venture Forth so you can cast it without paying its mana cost. As you cast that sorcery, Hermes, Overseer of Elpis steps in to spawn a 1/1 Bird creature token, which immediately fires off Mana Echoes to generate a surplus of colorless mana based on your growing flock of shared-type creatures. Because Venture Forth buries itself back into exile with new time counters every resolution, you can continuously pump the excess mana right back into The Tenth Doctor's Timey-Wimey ability to repeat the entire sequence.