Conqueror of the Frontier

When you cast Conqueror of the Frontier, pay {s}{s}{s}{s}{s} as an additional cost.
Conqueror of the Frontier is white.
You may exert Conqueror of the Frontier as it attacks. If you do put a token copy of Conqueror of the Frontier onto the battlefield tapped, it doesn't untap during your next untap step. (An exerted creature won't untap during your next untap step.)