The last part is drawn in a different style from the previous two. The main character's abilities are different from before (He can only make someone half a woman then that person needs to be cum to become a woman but in the last part he can turn someone directly into a woman). I can't read Japanese but I can see that the last part is sketchy and doesn't match the previous two. I thought Amulai Sweet Factory just wanted to end the story so they gave it to another artist.
@hoathan40000 Actually, he can turn someone into a woman just by touching them. Making them cum turns them into slaves that obey his every command. This was the case even in the previous two so his power isn't different from before.
The artstyle does seem to have changed but the same artist is credited so it's possible their art has changed in the years since the release of the previous two.
@Yuki Makoto You can read part 1 in English here: https://e-hentai.org/g/726450/bb706821b2/ The main character's abilities are different from before. If you pay close attention you will see: He can only make the target have woman 's boobs, the target must be cum to become a woman and his slave. After the target becomes a slave, he takes complete control of the target. I know an artist's style can change over time but in this case the difference is too great. Besides, the last part style doesn't match the style in Kirise's recent works. I noticed that out of Kirise's work, only Seiten Heni Vam-Pi-Re has the group is Amuai Okashi Seisakusho so I think Kirise might not work with Amuai Okashi Seisakusho anymore.
@hoathan40000 I can read Japanese just fine. It's mentioned by Amane that she had completely become a woman before cumming and becoming unable to resist Takeru's commands. That part is the same even in the earlier uploads so it can't have been changed.
Edit: It seems like I read the order of the panels wrong. You are right about his power. Sorry about that. Some of the dialogue in this new story does insinuate something similar about his power so it does still seem to be the same as before.
@Yuki Makoto I gave you the link to the English version part one because this Japanese version lacks the prologue and more importantly, the first time the main character's abilitie are shown to the reader.