Oh, and while we're talking about her, I've got to mention Sword of the Chosen - the sword of Selenia
Ugin is such a strong card, I frequently use it as a point of interest when a card is especially good when going up against it, such as Thought-Knot Seer or Nissa, Worldwaker
There are at least a dozen different Yu-Gi-Oh
Seeing as this card is legal in all formats where it could appear, the demand for it is quite high especially as a one-of in CEDH decks that can thoroughly abuse it in concert with token-producing cards, untapping-land shenanigans, and much more
But they are vulnerable to removal, have limited use, and can disrupt other players
Every time your opponent casts a spell, you're able to draw a card unless they pay a tax of one additional generic mana