What a coincidence! - I actually tried a Grass-only run this past week (because I was sick and stuck in bed) and somehow, this is the first time in my life that I realized that I'm actually quite bad at Pokemon strategy, so I had to change it to "MOSTLY Grass-types" to get to the end. Oh, the shame!
Anywho, Grass/Ghost is a cool combo, and I'm glad you liked the quiz! :)
Gen IX... like I said, I'm really bad at strategy, even with terastallizing . I'm legit impressed that you even got to Jasmine in Gen 2 with just Bugs, especially given the first gym. That Whitney fight must've been just awful (Heracross helps, I guess?)
I ended up spicing up my Grass guys with Fairy-types - similar vibe, and having a Klefki around to no-sell the Poison offense ended up being really helpful.
