Going to say a 3. She had a lot of potential, a LOT! However, she suffered from being a woman in Kishimoto's manga.
Good design. Elegant and beautiful, but demonic.
Evil; arrogant and greedy, paranoid, clearly driven crazy by power.
Ominous backstory and motives.
All the power! All elements, all kekkei genkai, all the Bijuus... didn't use any of it. She almost solely relied on her portals, bones, and chakra fists.