Winter Orb

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

As long as Static Orb is untapped, players can't untap more than two permanents during their untap steps.

{T}: You may play target snow permanent card from your graveyard this turn. If you do, it enters tapped.

Whenever Jorn attacks, untap each snow permanent you control.

At the beginning of your end step, untap all lands you control.