Lost Izalith

{t}: Add {r} to your mana pool
{t}, Add {b/r}{b/r} to your mana pool. Use this mana
only to cast demon spells or red/black instant or sorceries. Lost Izalith doesn't untap during your
next untap step
"The Witch of Izalith attempted to desperatedly
recreate the then fading First Flame. The ritual was a failure, and the chaos flames brought ruin to the city, killing its population and birthing the Chaos demons"