Mantle of the King

At the beginning of your upkeep, if your
commander is in the command zone, you may
put a storage counter on target land.
Lands you control have: "{t}, Remove X storage counters: Add {x}. If X is greater than 5, you may instead add X mana of any combination of colors.
Use this mana only to cast your commander."
(Your commander may normally bear only one of
each type of Regalia.)