Kroxa also sees play in Modern Jund and Rakdos Midrange to great effect, as you can fill up your graveyard so easily with fetch lands being in the format
Its nice to be able to experiment with a bunch of different high value cards and see what works before dropping loads of cash on original cards
You could make this deck work with the Poipole line, the Ekans line, the Alolan Grimer line (with the Promo A-Grimer card), or the Koffing line with a bit of tweaking, as long as youre running Nihilego and you can Poison your opponent
Personally, as a Magic player since the early '90s, working on the set has been such a joy because it combines the best of the early days of Magic with all the learnings and progress Magic has made along the way
Legacy Reanimator, Modern Swarm, and black Affinity decks all like the witch