Although the story so far has not indicated the extent of Shiny Coco's abilities, powered up or not, Chapter 13 seems to imply that the most powerful of the group of Magical Curry, Foret Noire, Pretty Saku-Nyan, and Lord Kaiserk the Maniacal Girl, is
Magical Curry. In Chapter 13, she was able to overcome Lord Kaiserk's Abyssal Hand with merely a 'twist of her wrist' ! The implication is that she is more powerful, albeit maybe only slightly more than that of Lord Kaiserk. Why, in Chapter 55, Pretty Saku-Nyan's power was able to subdue Lord Kaiserk at Yui's birthday party, showing the Lord does have limitations on her power. Plus, after the attack from Shiny Coco, it is only Magical Curry that is able to stand up and announce that she is not down and out yet ! It's possible that Magical Curry has the ultimate power, but is unaware or unskilled of how to access or use it to her best advantage. We will have to see how the story unfolds this close to the end of the manga.