Rings of Kynaios and Tiro

At the beginning of each player's upkeep, you
may add your choice of {w}, {u}, {r}, or {g}. If you
do this during an opponent's turn, that player
also adds their choice of {w}, {u}, {r}, or {g}. Until
end of turn, players don't lose mana added this
way as steps and phases end.
Equipped creature has "{t}: Add {w}, {u}, {r}, or {g}."
Equip {1}