Artwork source: https://gelbooru.com/index.php?page=post&s=view&id=1211655

Before this went poof on DA someone asked if I could tell a little about what likely happened after:

The rest of the occult club and Maria decide that they will work together and use magic to help Jake adapt to his new situation. They cast an illusion on his family, allowing him to return to his family, and use spells to re-enroll him at school with a female identity. They also give him a haircut and a new style to help him feel at least some ownership over his new body and identity. The girl responsible flees to a different school (witches always tend to get away with things). Maria insists she is straight, but they eventually become close, ambiguously yuri friends with lots of kissing.

Jake wasn’t intimidated by magic, and while a few of the girls in the occult club at school were a bit on the suspicious side, they'd never done anything to bother him. When his first-ever girlfriend Maria wanted to join the club, his only worry was whether she would be in for a letdown if she didn’t have any powers.

Maria was just a normal-looking girl who had gotten lucky. Despite being one of the only girls in their school to publicly have a boyfriend, she was rather innocent – their love was more like a puppy love, and she’d never even kissed him on the lips before, saying that she wanted to wait until it was the "right" time. And after he admitted that he’d never kissed anyone either, she made him “save” his kiss-virginity just for her. He never thought it was a big deal, though. But still, that pure heart was part of what he liked so much about her…

It was a regular Monday afternoon, and Jake was having a snack, enjoying the time alone before his mom got home, when he got a knock at the door. It was one of the girls from the club.

“I’ll get straight to business. You like Maria… right?” After hearing his affirmative, but confused, response, she continued. “I see. So you wouldn’t want to do anything to make her sad, right? So… sorry to ask, like this… But you never kissed a girl before?”

“Uhm… no? …” He saw her placing a circle of magic cards around him. He thought he saw a small smirk on her face, and he started to get worried. She said something quickly from the corner of her mouth, and then he was engulfed by an intense, but painless, flame.

“Pffftt… haHAHAHA!” As his head cleared, he saw her barely trying to cover her laughter. He tried to get up from his hands and knees, but he struggled and felt off balance. His whole body felt totally different… He tore his gaze from the laughing girl and caught a glimpse of himself (!) in the wall mirror!

Located there was a very attractive girl, with very long, draping blonde hair and red-brown eyes… Hanging visibly from her chest were a pair of large, weighty breasts that were probably around an F cup – and behind that was a round, just-barely-not-fat ass and a pair of thighs to match. And half-covering her enlarged rear end, he saw a short green skirt… which, if he remembered right, was the uniform from the private school in the next town over…

“Disappointing. Even a guy like you… You got to kiss that face, though? I’m almost jealous… What a slut, though.” The occult girl looked down at him with disgust and pity. “Never kissed a girl before, huh?”

Jake stayed frozen as his mind slowly worked out what had happened. He barely remembered now – a blonde, rambunctious little girl that used to live down the street when they were little… who must have moved away long before she grew her assets, and now almost unrecognizable… Even more worrying, though – supposedly, the reversal of even basic magic required exponentionally more skill and power…

“W-wait!…” his somewhat deep, sultry voice cracked upon using it for the first time – not helping his case as the girl’s gaze became even more suspicious.

“Oh, I still have one card left. But it's… Hmm. Alright, this should do.” She quickly wrote a magic phrase and stuck the card behind his skirt, letting it dissolve into the air before he could react.

Suddenly the air, which he was already feeling circulating around his mostly-exposed butt, felt sharp and cold. His ass cheeks instinctively clenched as the thought entered his mind, and a sobering feeling came across his thighs. He resisted, but after seeing the girl leave and lock the door behind her, there was no reason to hold back.

“Ughh.. Ugh.” Laying his face (and boobs) down on the floor, he reached backwards, only barely able to get around his new rear end. Upon feeling the warm feminine hand reaching at the edge of his panties, something awakened within him, and his horrific suspicion was confirmed…