By combining Marvin, Murderous Mimic with Pili-Pala and Bighorner Rancher, Marvin absorbs the activated abilities of both creatures to form a self-contained mana engine. With at least two power worth of stats backing the board, Bighorner Rancher's tap ability fuels Marvin to generate green mana, while Pili-Pala's untap ability converts that energy back into whatever color you need by spending just two mana to untap. Because Pili-Pala's activation costs two mana and untapping it generates one while Bighorner Rancher's green mana production can scale to cover the difference, looping this sequence yields infinite colored mana of any type.