Iris

Iris is a central figure in Death end re;Quest and a supporting character in Death end re;Quest 2. She is the "Proto-Ludens", built by Aphesis but going rogue after a certain tragedy.

End Quest
Iris, who is not named until late in the game, edits the heroines' memories and personalities to get them to act like the characters that they are supposed to be portraying. She later wipes their memories as it was causing bugs in World's Odyssey. She is given her name by Shina Ninomiya, who she forms a close bond with.

Death end re;Quest
At the start of the game, Iris is in her Enotoma form, and murders Shina. Arata then causes time to reverse so they can try again.

Shina is one of the 10,000 people kidnapped by Aphesis in an attempt to create a Proto-Luden, and they find Iris likes to talk with Shina. They spend a large amount of time together in World's Odyssey, though when Shina finds out about the kidnappings, she attempts to help and is shot to death. When Iris finds out, this causes her to go crazy, and she locks Aphesis out of the game. At some point, she is emailed to Arata by Shina, who was revived as a game character by the other Ludens. Aphesis then attempt to get her back.

When escaping from Aphesis towards the end of the game, Iris tells Arata which way to go.

Eventually, Arata is able to open the file, which summons Iris though she continues to go berserk. After defeating her, she dies in Shina's arms as Shina finally remembers her.

In Shina's ending, the two worlds are fused and Shina is reborn as a Luden, and Iris is her sister.

Death end re;Quest 2
In Death end re;Quest 2, Iris appears as an AI inside of Arata's laptop.

Other Notes

 * Mary Skelter 2 gives Rapunzel a costume based on Iris as part of its "Death End Attire" cross-promotion.