Mimiru Miltie is one of the heroines featured in Monster Girl Encyclopedia World Guide I: Fallen Maidens, and the parallel tales of Monster Girl Encyclopedia Stories: Fallen Brides
The black furred monster that appeared in town, a "baphomet," possessed immense power. After being overwhelmed and drained of her magic by the baphomet's spells, black tentacles formed from demonic energy, crawled around Mimiru's body and violated her. While her thoughts melted away from the pleasure. The expression of the baphomet gazing at her was gentle and full of warm affection like the way one would look at a young child. It made her mind recall "you."
She actually loathed both magic and her own talent: because of that, adults were relying on her and instead of being protected by adults, she was forced to fight for them instead; becoming a being that protects adults. Behind all the kind words and smiling faces, she knew that their acts were all a calculation meant to use her and that the truth was that many of them viewed her as an aberration and feared her.
She wanted to become a mere kid, who could pout when unhappy and be loved and accepted by others, so she kept intentionally doing things like "something that a kid would do"; "who can save me?" is what she asked herself. In that dark time, she met "you," who didn't change "your" attitude toward her. Even when she showed you her powerful spells and her mature thoughts and behaviors, "your" attitude towards her didn't change and that delighted her. In truth, she loved you and wanted to feel your touch; but she was so cynical that the only thing that would come out of her mouth was biting sarcasm.
Thus, due to the pleasure and power given to her by baphomet, the feelings for you that were buried in her heart burst forth and she ended up being reborn as a "witch." The knowledge of sorcery that she formerly possessed and the memory of the filthy adults she hated, were all melted away by pleasure and she totally forgot about all of it. The only thing that remained was her sweet desire for "you;" all she could think about was sharing intimacy with "you" and begging to play awfully obscene games. She felt most at ease while wrapped in "your" arms, joined with "you," and being given pleasure and spirit energy after begging for your affection satisfied her heart more than anything.
By becoming a witch, her originally high magic power swelled even further; although she had lost her knowledge, she is still able to use high level spells effortlessly. She often makes tentacles formed from her own demonic energy crawl all over her body so that she can remain in a state of ecstasy and keep "you" on her mind without much effort. When she is playing dirty games with "you," she uses a variety of obscene spells to drive you wild and enhance the pleasure. Now, she doesn't have to think of difficult things anymore at all; just by being in her beloved "big brother's" arms, she feels that "you" will protect her. From now on and forever, she can spend her life with "big brother" as a monster child and that makes her unbearably happy.
"Magic...? What's that? Forget about it; why don't you play with me?
I've been touching myself a lot to get ready for big brother. Touch me a lot. Give me a lot."