K'rrakus, Mountain Monster

When K'rrakus enters the battlefield, choose a
basic land type and untap each land of the chosen
type.
Whenever you cast a spell with X in it's mana cost
you may double the value of X, if you do, K'rrakus
deals twice X damage to you.
When K'rrakus dies, choose a basic land type,
each player draws cards equal to the number of
lands they control of that type.