Lars and Krista, Twins

This spell costs {1} less to cast for each snow land
you control.
When Lars and Krista, Twins enters the battlefield, tap all creatures your opponents
control, they don't untap during their controllers
next untap step.
Whenever you cast your first instant or sorcery
spell each turn, copy it. You may choose new
targets for the copy. If that spell was snow, copy
it twice instead.