Neris

Neris, or Alipheese Fateburn XVII (Seventeenth), is the daughter of both Luka and Alice from the authentic history, and the sister of Nero.

Biography
Neris is first mentioned after meeting with an elf in Enrika.

Now that Alice the 16th has vanished, three new contenders for the Monster Lord title have arisen. Alice XV, Alice the VIII and Alice XVII.

No-one knows a great deal about this mysterious new Alice. She just showed up. But on the day she did show up, she took control of the whole of Plansect Village (which is measured in the thousands), fought Cassandra and won, drove the entire Arachne faction, lead by the Spider Princess, into a cave, and finally, fought Granberia to a draw. Alone. In one day. Although, the reason she didn't beat Granberia was that she was already exhausted, and couldn't reveal her true power. Otherwise, the fight would have been over in seconds.

Neris first appears in the Cave of Treasures.

Luka and the party need Poseidon's Bell, but Nanabi is guarding the entrance, so the party is forced to fight her. At first, the fight is going in the favor of Nanabi, but the 17th intervenes, and attacks Nanabi with Vaporizing Rebellion Sword, dealing over 20,000 damage.

The party is bewildered by her random appearance, but Tamamo walks in, seemingly to investigate the commotion. Instead, she treats Nanabi as if she were in a sealed form, and that Kitsu is with them. She also addresses Luka as if he beat Nanabi alone, and not Neris. Neris explains that it's not the real Tamamo, and it's just been "copied and pasted" from another source. The fundamental reality. And only one person has the power to do this.

Just then, White Rabbit appears before them and is disappointed to see that she was found out by Neris. She's also upset to find there are now eight Alice's running around, meaning more work for her. But unlike the rest of the Alice's, Neris is doing the opposite of what they're doing. Altering this timeline from the original, meaning chaosization will occur faster. Whether Neris is aware of this, cannot be said. White Rabbit threatens to erase Neris, but Neris replies that would be breaking her own rules. The White Rabbit is meant to guide, not intervene. White Rabbit counters that since Neris is not from this world, the rule doesn't apply to her. In addition, erasing her would have no danger of spreading the chaos.

White Rabbit stops time and attempts to erase Neris.

Suddenly, Nero materializes behind the White Rabbit while time is still stopped, and whacks her with Flash Kill before she can react, dazing her. White Rabbit is confused that Nero could do that, as time should be stopped. He mocks her for thinking she is the only one who can control time, and teleports elsewhere, along with White Rabbit. Naturally, no one else saw that, as time was stopped. To them, White Rabbit vanished on the spot. But Neris knows what happened.

After that little incident, Neris decides to ask if she can go out on a date with Luka, bewildering everyone. Luka asks if she is the 17th, but she asks Luka not to call her the 17th, and call her by her real name, Neris. She suggests that they both go somewhere like the Oasis, or Grandeur, the Coliseum, or even the Academy of Magic. Or they could just skip to the fun part. The shocked Ilias tells her that Luka is her subordinate, and she cannot simply do as she pleases with him. Neris prepares to leave and tells Luka that she won't take no for an answer next time, and she vanishes.

The last time she appears in part 1 is in the Forest of Spirits.

Luka was attacked by the Armored Berserker in the Forest of Spirits but was ultimately too weak to fight him. He is about to deal the final blow to Luka, but Nero steps in, and stops time, blocking his attack. Neris teleports in shortly after. Nero asks Neris to take Luka, and everyone else to a safe location, while he deals with the Berserker. Neris is concerned for him fighting the Berserker alone, but Nero responds that he'll not be a problem. Neris teleports Luka and his companions back to the Pocket Castle while they're unconscious. Nero then proceeds to deal with the Armored Berserker alone.

Neris and Nero in Part 2 later helped Luka against Tamamo no Mae from the Monster World alongside Tamamo from Paradox Nero tells Neris to not hold back at this exact moment they revealed their true form shocking Alice/Ilias and wonders why they look like Luka and Alice.

By this point, it's safe to assume that Neris and Nero are Luka and Alice's children from the original timeline, making them brother and sister.

Trivia

 * Neris is 1-4 human, 1-4 angel, and 2-4 monster.