So, on its own, I would not recommend using this card in a deck, the main reason being that it cannot do any damage when attacking, plus even if you do put the defending Pokemon to sleep, if they get a heads when they flip a coin, they can attack like normal
Just having a Dack in play doing nothing but looting each turn generally equals a win even without any graveyard synergies on the go
And you wouldn't necessarily have to wait for that Pokmon to be positioned in your opponents active spot either, as the Item card Counter Catcher could be used to pull them into play
Meanwhile, the whole "Yugi almost dies in a fire" plotline that concluded the arc got shoved into the Yugi vs
Rest them and give one Charlotte Linlin card Double Attack or Banish
So while this Medusa is probably worse than Lady Tremaine, Tremaine is a great card and there is room in decks for cards that are similar to Tremaine but not quite as good