Em, Daughter of Storms

At the start of your combat step, flip a coin:
Heads: Islandwalk. Tails: Swampwalk.
When Em, The Daughter of Storms deals combat damage to a player, choose one.
Steal: That player discards a card. Draw a card.
Strand: Tap target creature that player controls.
It doesn't untap in their next untap step.
Storm: The next instant or sorcery spell you cast
this turn that targets that player, or a
creature they control, gains 'Storm.'