Nico should be the most over powered in the crew. I hate how she just kinda melded in to the background. She starts out powerful enough to be Crocodile’s right hand. She took out Tashigi and all those marines in the Alabasta Arc and saved Luffy and the crew. Making her the weak, woman that needed to be saved in the Enies Lobby Arc was horrible. I get that she gave up her will to live but that wasn’t really even developed into her character after she escaped in the Going Merry.
Her devil fruit ability should be an advantage to everyone in the crew. She’s curious and well read so why would she learn from the crew when she’s not deciphering old text. In the mean time she should be learning everything from the other crew members. Her hands would make it perfect to learn to be a thief from Nami, cutting purses, using slight of hand, cracking safes while being her own look out. Fixing things with Franky, since she can use more then one tool at a time. Chopper could show her how to suture and bandage. Robin should be an up close threat and a ranged threat if she learned swordsmanship and marksman ship from Zoro and Usopp. She wouldn’t necessarily even have to learn Haki from Luffy, if someone can use Armament Haki she should just be able to form her hands at the point of armament and attack with it.
She should be one of the monsters instead of Sanji.
I really dig her with Usopp. The way she brings up morbid and spooky conversations to freak him out is is cute. I really hope she has to save him and take care of him this arc.