Serendib Efreet's artwork was fixed, but the artist's name wasn't updated (same for Plateau, which also didn't include the correct artist credit)
Yenna lets you set up some potentially big plays, copying enchantments like Enchantresss Presence to draw double the cards, or even copying game-warping enchantments like Overwhelming Splendor
Harmonize works like flashback, but you also get some optional cost reduction
It has been responsible for entirely stagnant metas in Magic history due to its high power and ability to circumvent fundamental rules around drawing cards
(6/16/2023) Each time the Ring tempts you, you must choose a creature if you control one
The latter is really good with the recursive dorks, be that Butcher Ghoul style or Gravecrawler