Combo Grinning Ignus +Ruby Medallion +Runaway Steam-Kin + Magic: the Gathering MTG

With both cards in play and Runaway-Steam Kin with three counters: Remove three counters from Runaway Steam-Kin to add 3 red mana Pay one mana to activate Grinning Ignus' ability, returning it to your hand and adding 2R Pay 1R to cast Grinning Ignus Runaway Steam-Kin's ability will trigger, gaining a +1/+1 counter Repeat the process two more times to give two more counters to Runaway Steam-Kin Then remove the counters from it and repeat the process for infinite colorless mana.

Legallity