Time Sieve + Myr Battlesphere + Planar Bridge + Epitaph Golem

Time Sieve

Myr Battlesphere

Planar Bridge

Epitaph Golem

How it works

1. Activate Planar Bridge by paying 8 and tapping it, causing you to search your library for Myr Battlesphere and put it onto the battlefield.
2. When Myr Battlesphere enters the battlefield, it triggers, creating four 1/1 Myr artifact creature tokens.
3. Activate Time Sieve by tapping it, sacrificing Myr Battlesphere and the four Myr tokens, causing you to take an extra turn after this one.
4. Activate Epitaph Golem by paying 2, putting Myr Battlesphere on the bottom of your library from your graveyard.
5. Repeat each turn.

This engine transforms heavy mana into an unstoppable loop of extra turns by constantly recycling a single metallic army. You start by using Planar Bridge to fetch Myr Battlesphere straight from your library, instantly flooding the board with the four Myr tokens it brings along. Those five fresh artifacts feed directly into Time Sieve, satisfying its sacrifice requirement to secure an extra turn. Once everything hits your graveyard, Epitaph Golem steps in to tuck Myr Battlesphere right back onto the bottom of your library, making it fully accessible for Planar Bridge to find all over again on the next rotation.