XFRISK

During the XTale comic, it's revealed that XTale!Frisk possesses the power of Overwrite. When speaking with XTale!Sans about what happened, they summon the Overwrite Button. It's known that they only possess half of XGaster's soul, which they share with X-Event!Chara. Thanks to the weakened state of XGaster's soul, this allows them to use the full potential of OVERWRITE. With half a soul, they can also alter numerous outcomes in a timeline without needing to reset it. X-Event!Frisk also has the ability to summon knives and, presumably, other weapons.

XTale!Frisk initially appears like many other versions of Frisk: quiet, shy, monster-loving, and kind—characteristics of a true pacifist. This changes when XTale!Sans is forced to carry out orders he would never otherwise obey, such as sacrificing his dignity to kill XTale!Frisk. He then reveals another side: a vengeful and destructive human, willing to risk lives to get what he wants. However, he cares for Cross, even though Cross doesn't ally with him, as he cried when XTale!Papyrus struck him hard and, on his deathbed, gave Cross his necklace, meant for his best friends. He also shows concern for the other monsters in his timeline.

Frisk from XTale is characterized by a predominantly black and white color palette, with the exception of their necklace and eyes. They have short, gray hair, wear a white scarf (which appears light gray in the Underverse scene) tied at the nape of their neck, and a simple white T-shirt over a long-sleeved black shirt. Like most characters in XTale, they wear a heart-shaped pendant. They wear knee-length black shorts and white boots. Towards the end of XTale, it is revealed that their eyes are similar to XGaster's: red in the right eye and purple in the left.
It measures 1.85 cm

Frisk is born in the XTale universe on July 7th, son (or at least creation) of XGaster (or adopted) and brother (or created together) of XTale!Chara.
The universe of XTale is an experiment by XGaster: his idea is to create, rewrite ("Overwrite"), reset timelines, in search of a "perfect world".
Frisk starts out as a relatively "normal" child in this universe: shy, kind, peaceful.
As XGaster manipulates the universe, Frisk and Chara rebel against him. However, during Timeline IV (and beyond), Frisk is "Overwritten" with a genocide code.
Frisk becomes the vessel of the so-called "X-Event," an entity of immense power linked to the ability to overwrite the timeline. This makes them a semi-antagonist/central antagonist.
Frisk's personality changes: from being kind to becoming vengeful, using their power to manipulate events, timelines, sabotaging the reality of the XTale universe.
Timeline IV: Frisk obtains their "genocide code", attacks cities, Chara intervenes.
Timeline V/VI: Frisk and Chara are rejected, Frisk refuses to train with Undyne, their mood becomes darker.
Timeline VII/VIII/IX: The fusion with Chara occurs, Frisk loses part of their soul, becomes X-Event!Frisk, and is shown more as a total antagonist.
Finally, in the confrontation with Cross (who was X!Sans in disguise), Frisk is killed (or at least their soul is absorbed). They are later revived by XGaster in the series' epilogue.

Relations:
XGaster (his alleged father)
XTale!Chara (their supposed sibling)
XTale!Asgore (his adoptive father)
XTale!Toriel (her adoptive mother)
XTale!Asriel (his/her adoptive brother/sister)
XTale!Muffet (crush/close friend)