The Caligula Effect 2.
Story, characters and graphics are all horrible shit, but boy am I enjoying the heck out of the unique turn based combat system.The UI is serviceable.
Character building is like in FF IX (certainly other games did this before), where you learn passive skills from items. Once you have mastered them after some combat encounters, you can use them without needing to equip the item. You have 6 free slots for the passives.
Some quests can only be fulfilled by equipping those passive skills/items like salesman for example. With it equipped you will get the information to fulfill another quest. Nice little mechanics.
On normal, I found the difficulty too easy, but the last boss I fought, was a 20 minute, struggle to survive wake up call. I'm only 10 hours in, so the game might turn to shit.