Requires

Myr Propagator must be on the battlefield. Mana Echoes must be on the battlefield. Samut, Voice of Dissent must be on the battlefield. Mana needed: at most

Steps

1. Activate Myr Propagator by paying and tapping it, creating a token copy of it.
2. When the Myr Propagator token enters the battlefield, Mana Echoes triggers, adding for each Myr you control.
3. Repeat using the Myr Propagator token instead.

Results