Theres a few cats with removal as part of their enters abilities, and you can use cards like Elesh Norn, Mother of Machines to double those triggers
With certain playgroups, I'd slot this in without any other discard support
6 Yedora, Grave Gardener While she doesnt provide anything in the way of mechanical boosts for your other Treefolk, Yedora does provide a nice flavor boost, letting your fallen Treefolk (and other creatures) live on as Forest lands after their death
Notably, her first ability allows her to draw a card on other players' turns while also potentially dealing damage on other players' turns if she casts a spell outside of her own turn
Fabled, or set nine, includes a lot of reprinted cards from the first four sets The First Chapter, Rise of the Floodborn, Into the Inklands and Ursulas Return because theyre officially out of rotation
Use enchantments like Teferis Tutelage and Fraying Sanity for passive drain