Ueki no Housoku, JoJo no Kimyou na Bouken Part 3: Stardust Crusaders Recommendations
I feel like the main characters and the general flows of the shows are similiar.
You get a main character who suddenly aquires a power, both of them are flegmatic in their own way at times, but when needed, they fight with unfaltering resolve.
The side characters have their own deep, most of them with a flashback of their own, explaining their actions.
Also in both shows there are motives of journey, tournaments, ability fine-tuning, (few others but *spoilers*), but most importantly using one's with to overcome your opponent (even though i felt like JoJo was better at that.)
Each of the shows has its own pace, with