So, going through the game makes it obvious the balance is in a pretty rough place after multiple updates (some skills are even completely unable to deal any damage to higher level Dominas due to their high defense stats). The perk and skill systems were added several years ago, and while they were fine for their time, they need a lot of tweaking to make them scale up to more recent content. However, even fixed, I'm not fully convinced they add something significant to the game. Sure, it's nice to have build variety and multiple paths to becoming stronger, but the game in general is fairly linear story-wise, so I'm not sure it should focus on replayability that much at this point. I think redesigning the levelling system in a more plot-based way would be more interesting, with less possible paths and specialization, but with your chosen skills interacting with the Dominas and the story in more ways than just the combat.
The old system contains dozens of different skills tied to each class, which is fairly hard to balance reasonably. A new system could instead focus on just 3 character paths/classes, and have the skills you learn get noticed and commented on by the Dominas, have uses on the map or during the story instead of just during combat, etc. In addition, the old skill/perk system we're using isn't compatible with Android and it's the main thing holding back an official Android port (it works, but scrolling the perk tree is cancerous).
How fond are you of the current perk tree / levelling system? Would you be willing to ditch it to have an Android port instead?