Being difficult to counter also helps, especially in any blue control-heavy meta
Like most Magic: The Gathering cards, the value of Xanathar, Guild Kingpin depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Adventures in the Forgotten Realms)
Chord of Calling In a go-wide green deck, Chord of Calling is the best creature tutor
single target removal, and the ease of having them in hand when needed) having certain staple land and mana cards So far this has been helpful, but whenever I ask how exactly they come to the conclusion of their deck's power level, I usually receive a shrug and/or blank stare (or find articles that beat around the bush)
Fill your binder
Nature lovers will enjoy the sunny style