There are a couple of bonuses that we can make use of, but I dont think its enough to make Stuck in Summoner's Sanctum more than just a moderate playable
There are plenty of answers for her to remove her straight away, but if she gets to her second turn shell turn things around quickly
Ursula, Deceiver of All boasts incredible artwork that's instantly recognizable as a unique form of one of Disney's very best villains, as well as a flashy effect that doubles the power of song cards
But the card can pull some weight in Equipment-only mode, as the power-toughness buff it provides is decent, especially on a smaller mana value creature
If the target creature is a token, the ability still triggers when it dies, but you won't return the token to the battlefield because it'll cease to exist when state-based actions are checked
Notably, many of the character cards also feature a version name (for instance Spirit of Wonder, for Elsa, or Shapeshifter, for Merlin) which does differentiate them from one another