Nylvana, Frostbringer

Partner with a snow creature (You can have two commanders if they are Nylvana and a snow
creature. The snow creature doesn't have to be
legendary.)
When Nylvana, Frostbringer enters the battlefield, tap up to three other target creatures.
They don't untap during their controllers' untap
step for as long as you control Nylvana.