Many legendary-matters tools come from sets and releases such as Dominaria United and the Universes Beyond release The Lord of the Rings: Tales of Middle-earth
The story of Eldritch Moon is about how Eldrazi influence on the plane is warping the planes already very frightening denizens, and Docent of Perfection isnt immune to that
This is an extremely powerful commander (and certainly a popular one, with over 15,000 decks), since she can cheat out very expensive creatures for free, with none of the drawbacks we see with similar creatures like Ilharg, the Raze-BoarIlharg, the Raze-Boar and Hans ErikssonHans Eriksson
Rather than paying two to go get one land, like our Warped LandscapeWarped Landscape example, Myriad Landscape will go get you two
Additionally, the card itself is disgustingly powerful
Use the creature's toughness as it last existed on the battlefield to determine how much life you gain with South Wind Avatar's second ability