Sure, itll let you steal an opponents legend, which could be their commander, but it also dies swiftly to a ping or a board-wide -1/-1
I've compiled a few popular cards with at least three pips in each color for you
The Mycotyrant One generic, one black, one green, Legendary Creature - Elder Fungus - */* - Mythic Rare Trample The Mycotyrants power and toughness are each equal to the number of creatures you control that are Fungi and/or Saprolings
Options are very limited in Frontier for cards that refund mana when they enter the battlefield, that is, outside of colourless mana from Eldrazi Scion tokens
While it seems unlikely that another printing at Mythic Rare will do much to put a dent in the hefty price tag that comes with this card, Im very satisfied with the amazing new artwork by the inimitable Richard Kane Ferguson
The way I see it, you could build this either as a go-wide tokens deck filled with low-cost artifacts that either ramp or bring value, or tread down the aristocratic path