(: Add or to your mana pool.)
At the beginning of your end step, if you didn't cast any spells this turn, Molten Heights deals 1 damage to you.
: Molten Heights becomes a 2/1 red and white Beast creature until end of turn. It's still a land.
: Add 
or 
to your mana pool.): Molten Heights becomes a 2/1 red and white Beast creature until end of turn. It's still a land.
