arena of glory enters the battlefield tapped unless you control a mountain.
t: add r.
r, t, exert arena of glory: add rr. if that mana is spent on a creature spell, it gains haste until end of turn. (an exerted permanent won't untap during your next untap step.
t: add r.
r, t, exert arena of glory: add rr. if that mana is spent on a creature spell, it gains haste until end of turn. (an exerted permanent won't untap during your next untap step.
