Wiki got chubbier and more comfortable with herself as the years of lucy's love and appreciation went by
She starts off as a throne angel, to interact with humans she takes human form, an androgynous person, but the more she interacts with Lucy and the more she learns about human gender the more she takes form as a girl, it's just more comfortable. She ends up enjoying being a human girl so much she can no longer turn back into her original angel form, but wiki's happy about it, she loves all the human traits she gained, she loves that she turned into a human like Lucy, she loves eating food, she loves that her body changed, she loves that she ages, there are some leftovers of her old angel self such as wings, weirdly colored skin and her halo, but she is not much more than a regular human girl who used to be an angel. She loves it, she loves being a lesbian.
Oh and lucy, despite looking like a demon she's nothing special, she's just a girl trying to live her life, she's also trans and has underwent treatment since early age and has a sci fi pussy from the future and she loves it.