Mahou Shoujo Hikaru

Hikaru undergoes a transformation where her body becomes voluptuous with large breasts, representing her most powerful state of magical energy in the future. She transforms by donning a squid-like creature, with her new form being inspired by both a squid and a demon. Her eyes become sharper, her personality becomes more upbeat and confident, and she also reveals a more ruthless side. She is constantly stimulated sexually by the tentacles' cilia, causing her to be in a state of sexual pleasure. Using her powers further enhances this pleasure.