Arena of Yuria

{t}: Add {1} to your mana pool
{t}, {2}: Choose target opponent, you and that
player each choose one creature you control.
Those creatures fight each other. If a creature
controlled by either player destroys another
creature by this effect, that creature's controller
makes 3 colorless Treasure artifact tokens with
"{t}, Sacrifice this artifact: Add one mana of any
color."