Preston Garvey, Minuteman (Surge Foil) (PIP-536) - Fallout Foil

At the beginning of combat on your turn, create a green Aura enchantment token named Settlement attached to up to one target land you control. It has enchant land and "Enchanted land has ': Add one mana of any color.'"
Whenever Preston Garvey attacks, untap each enchanted permanent you control.