Illyasvel, Miyu y Kuro (Fate Kaleid Liner Prisma Illya) Vs Dante, Vergil y Nero.

She is introduced to the world of magic by Rin and the Kaleidostick, Ruby, which leads to her forming a contract to become a Magical Girl. She initially finds it to be a fun experience, but after some time, she begins to see it as a burden. She often wishes to simply forget everything about the world of magic, which angers the people around her. She has some sort of great magical power sealed inside of her, which allows her to instantly harness vast power and knowledge of magecraft and class cards, such as the ability to use them to become one with a Heroic Spirit, while in mortal danger. She completely loses consciousness and attempts to remove the threat, regardless of the safety of her allies, and wakes with no memories of the events. This power has something to do with Kuro's existence, and it's existence is known by Caren and Irisviel, who tells Illya to embrace it rather than fear it.

Miyu Edelfelt is a young girl who serves under Luvia as a magical girl. Her origin is unknown, except that she has a brother who looks similar to Shirou, and she takes on the Edelfelt name after being taken in by Luvia. She lives in Luvia's mansion and acts as her maid to earn her keep. She uses Ruby's sister Kaleidostick, Sapphire, in order to transform, and she initially has a much better understanding of her abilities than Illya. She takes her role very seriously and treats Illya as a bothersome rival, though they eventually become close friends. She later gains the ability to use the Saber class card to embody the Heroic Spirit after seeing Illya preform it.

Kuro, initially referred to as Dark Illya, is a being created from Illya's hidden power and the Archer Class Card. She comes into existence after Illya uses the Class Card in order to save herself, and afterward, she falls unconscious and wakes up to find the card missing and an exact duplicate of herself, with the exception of dark skin and the Archer outfit, in its place. Kuro immediately escapes and makes various attempts on Illya's life, stating that they cannot both freely exist. She is eventually captured and has a seal placed upon her that forces her to share all sensations with Illya, including injuries and pain. Unable to freely fulfill her goal, she attends Illya's school as her cousin, Kuro, though she still holds resentment towards Illya. She is at odds with Miyu, who wishes to kill Kuro in order to protect Illya.
Having received most of Illya's magical power, Kuro is extremely powerful, capable of using all of the Archer class' abilities to a high degree, and easily able to overpower magical girls and even Miyu's Saber class change. She has the ability to drain people of their natural prana through the act of kissing, which leads to certain comedic situations. She has yet to reveal the exact nature of her existence, but she becomes extremely depressed when Illya attempts to deny magic, stating that it is essentially denying her as well. Caren states that her current existence can be considered a miracle.