Cross!Chara

X-Tale!Chara (also known as Cross!Chara when he's too cool with Cross in his phantom form, and X-Event!Chara) is the main antagonist for both X-Tale and Underverse, and only a minor character in The Truce. X-Tale!Chara was originally a child of XGaster, and after Ink!Sans shows him the multiverse, XGaster begins his experiment with X-Tale. With each new timeline, someone related to X-Tale!Chara would die thanks to XGaster. After a few more timelines, X-Tale!Chara and X-Tale!Frisk rebel against XGaster, but are both defeated and X-Tale!Chara ends up being overwritten into X-Tale!Frisk.

"You're only a piece of code with a scripted story. Whatever you say, I don't care.."

XGaster decided to experiment more on them, giving them his overwriting powers. X-Event!Chara, though, ends up destroying X-Tale, but not before he's taken over by Cross, still keeping him in his phantom form. Ultimately, it would be Underswap!Chara to give him a full body.

The Truce
X-Tale!Chara

After The Truce/Before X-Tale
With each new timeline of X-Tale, X-Tale!Chara would be adopted by X-Tale!Toriel and X-Tale!Asgore, but in the end would lose their loved ones and are forced to reset. This persists until X-Tale!Chara and X-Tale!Frisk were fed up against XGaster's doings, and try to stop him from doing his "New Experiment".

They both failed. X-Tale!Chara is overwritten to be a part of X-Tale!Frisk's soul, and XGaster granted them the ability to overwrite by taking half of his soul to theirs.

X-Tale
X-Event!Chara doesn't make an appearance until during X-Tale!Sans' dream, which he tells him that he'll be his best friend soon.

He makes further appearances as his phantom form, telling XEvent!Frisk about his plans, and asking if he's okay after X-Tale!Papyrus hits his brother hard.

After X-Tale/Before Underverse
Now living within Cross, Cross!Chara decides to closely examine his relationship with Ink closely. After Error takes their soul, Cross!Chara is able to come free from Cross, and he escapes his lonely universe.

0.0
Cross!Chara intercepts Sans' own world with his to explain that his timeline won't change when he's involved. Not liking the idea, Sans nearly kills the both of them, but explains to him why he needs to stay, before taking half of his soul, as fake mercy. Proclaiming that he'll take a break forever, he's suddenly interrupted by Ink!Sans, explaining that he'll never find happiness in someone else's timeline. He breaks into a fight with the both of them, but defeated and imprisoned. Just before they could ask him why, Cross!Chara said they needed their own universe, and leaves with his half soul.

0.1
Now back into their own universe, Cross!Chara tries to explain why they're doing this, and ask if he's scared, telling him that they would've wanted this. After absorbing the soul, Cross!Chara tells him of the other universes, and once Nightmare!Sans shows up, Cross!Chara tells Cross to negotiate a deal with him.

0.2
Now in Underfell, the two of them begin performing The X-Event, thanks to Cross!Chara's code. Once Cross is impaled by Underfell!Sans, Cross!Chara begins his assault on him, and pronounced that he's the X-Event.

When Sans starts questioning on XGaster, Cross!Chara tells him to leave the place, at which once Underfell!Sans is released from Ink, Sans throws his slipper at them as a joke. This was enough to distract the both of them for Underfell!Sans to be freed from his control and starts to severely harm Cross (not knowing that he was also harming Sans himself) and Cross!Chara helps Cross escape Underfell!Sans's Gaster Blaster attack.

0.3
Though with the Underfell Snowdin in their grasps, Cross!Chara isn't satisfied over Cross inability to get a human soul for him. By convincing him to sleep, he talks control of Cross, but doesn't get any further, as Cross impales his left eye to knock Cross!Chara out. Once Cross himself is knocked out, and Sans's soul is taken back however, it leaves a potential spot that Cross!Chara used to get 95% of Underswap!Chara's soul, bringing him back to his normal form.

With this, X-Event!Chara also has the ability to overwrite at his will. He overwrites the Underswap crew to kill themselves, then transform Underswap!Sans & Underswap!Papyrus into amalgamates that goes against Ink after he's denied from taking his white vial. Once the Underswap crew is reverted to normal, Underswap!Sans goes at war against X-Event!Chara, but he immediately stops to talk with "Cross". Nightmare is bored of this, and allows X-Event!Chara to kill someone.

On the verge of this, X-Event!Chara forces Underswap!Sans to kill him, which would also kill Underswap!Chara. Underswap!Papyrus stops this and accepts his death by X-Event!Chara, and would've died had not Sans took X-Event!Chara's hit, which turned out to target his ketchup bottle. He explains to Sans that his world isn't what it was meant to be, and tells him to kill Ink, but despite this, Nightmare had enough, and after stabbing Underswap!Chara, X-Event!Chara leaves and tells him to "spend his last moments".

Xtra Scene 2
His pre-0.3 self can be seen in Undernovela in Error's dream. Cross!Chara refuses to take Undernovela!Frisk's soul being that they have a mustache that they don't find very polite. Cross complains about this, citing that if he doesn't take his offer, he'll take a monster soul instead to shut him up. Their continued arguing is what allows Asgoro and Sins to enter in to demand Undernovela!Frisk back.

Appearance
In his standard form, he wears a black undercover, a white T-shirt, black shorts, white boots, and a white cape at his back. Like all the other X-Tale, he also dons a heart locket. His eyes in The Truce were originally normal, but due to the experiments performed by XGaster, both of his scleras are completely black, with his right pupil being red and irregular, and has a scar on it. When he's corrupting code, his left eye also become irregular, with the colors being purple instead.

While in his phantom form or his soulless form, he wears a white jacket instead of his T-shirt. Also gone is his heart locket and cape for that matter.

Abilities
As a phantom, he can convince the person who's hosting his soul to perform certain actions, and if they're unable to, they'll just take over instead. Once he has a human soul inside him, he can, and only then, can he overwrite. He's also quick at dodging attacks, and can spawn an array of knifes.

Behavior
Before the intervention with XGaster, he used to love everyone the way they are, but with each timeline, they grew more and more frustrated until eventually, they fought back.

Once X!Gaster transforms him to the X-Event, he plots with X!Frisk for everyone to kill X!Gaster. Later on, his experience with Cross wasn't really a nice one, as he tries to manipulate him into doing things he wouldn't do, and verbally insults him and others he finds unremarkable. After he gets a human soul, he's shown to be a sadistic child who would continued to make everyone suffer at his own will. Even so, he's too much of a talkative person, where his chats would eventually bore Nightmare!Sans.