The Misfit of Demon King Academy Episode 4

"I am the Demon King. Anos Voldigoad"

- Anos to Ivis Necron

15th Birthday (十五の誕生日) is the fourth episode of The Misfit of Demon King Academy anime series.

Synopsis
Misha confesses the shocking truth that, “At midnight on my 15th birthday...I’m going to disappear...” Misha was never supposed to exist in this world in the first place, but due to Ivis Necron’s magic, she was living a transient life. She had resigned to her fate that she will only live for 15 years, but Anos tells her, “There are two things that I do not understand. Regret and saying that something is impossible.” The misfit crushes the tragedy and unjust fate that binds the two sisters.

Summary
When Sasha was a fetus, Ivis split her into two babies so that when they turn 15, they would fuse back into a single more powerful demon. Anos catches up with Sasha, who is eventually revealed to be doing all of this to save Misha and has created a spell to let Misha live while she disappears. For the spell to work, Misha has to reject her and that's why Sasha always treated her poorly. However, Misha refuses so they tearfully wait for Misha to disappear. But Anos reveals that if he sends them back in time, they can fuse their half-sources with the half-sources from their unborn fetuses, so they will be born with complete sources as true twin sisters.

Suddenly, Ivis crashes from the roof and stabs Anos, revealing that he plans to use their fused body to host the true reincarnated Demon King. Unaffected by the injury, Anos grabs the demon sword and throws it toward Ivis, incapacitating him. He then activates Rivide to send them back, only to be blocked by Eugo La Raviaz, the Keeper of Time. Ivis and Eugo fuse together and they kill Anos.

However, Anos resurrects using Ingall and reveals that he has enough power to even defy a God. He then sends the twins to the past to fuse with their unborn selves and summons Venuzdonoa to destroy Ivis. Afterward, Anos resurrects Ivis, as he noticed that he was fused with a third, unknown source. He returns all of Ivis' unaltered memories and suggests that Ivis was taken over by someone working for Avos Dilhevia. Sasha and Misha return, now as true sisters with separated sources. Despite having saved Misha and altering the past, Anos nonchalantly decides to return his scepter to get a perfect score for the exam.

Adaptation Notes
Differences from the light novel:
 * In the light novel, after Anos is stabbed by Ivis with Gadol, Misha builds a steel jail around Ivis using Iris while Sasha uses her Magic Eyes of Destruction on him. However, Ivis easily suppresses Sasha's Eyes and destroys the steel jail. This was removed in the anime.
 * Immediately after obtaining Eugo La Raviaz's powers, Ivis is fused with the Scythe of the Time God. But in the light novel, he only fused with it after using a fusion spell on the scythe.
 * In the light novel, Anos and Ivis fight using various spells before Ivis fuses with the scythe. This was removed in the anime.
 * In the light novel, Anos, Misha, and Sasha go to Anos' house in the morning of Misha and Sasha's birthday, but this was removed in the anime.