Marvin, Murderous Mimic + Pili-Pala + Sanctum Weaver

Marvin, Murderous Mimic

Pili-Pala

Sanctum Weaver

How it works

1. Activate Marvin using Sanctum Weaver's ability by tapping it, adding at least two mana of any color.
2. Activate Marvin using Pili-Pala's ability by paying 2 and untapping it, adding one mana of any color.
3. Repeat.