Marvin, Murderous Mimic + Morphling + Doc Samson, Super Psychiatrist

Marvin, Murderous Mimic

Morphling

Doc Samson, Super Psychiatrist

How it works

1. Activate Marvin using Doc Samson's ability by tapping it, adding at least .
2. Activate Marvin using Morphling's ability by paying , untapping it.
3. Repeat.

The secret to this transmutation lies in Marvin, Murderous Mimic assuming the forms of both Morphling and Doc Samson simultaneously, granting it all of their activated abilities. While Morphling’s blue mana investment provides a free untap loop, Doc Samson provides the crucial engine work: whenever counters would be placed or power is leveraged, Doc Samson's replacement effect scales its tap ability to generate excess mana. By tapping the mimicked artifact creature for more than enough mana to pay for the untap, you can endlessly loop the process to yield infinite colored mana.