the actual story

the story starts a bit like fnas, but with some diffrences, clone tails was a lot into mechanic stuff, like his creator, but also a bit of a sience guy, one time he tried to built a portal as he had a theory about alternative universes, but an error happened, and he ended up in the UT universe in snowdin, he was understandably confused, and eventually ended up face to face with sans, who welcomed him, clone tails was rightfully skeptical of both him and papyrus initially, but over time became friends with them, sans, believing he could trust clone tails, taught him his abilities, so clone tails learned to teleport, use bone magic, gaster blasters, etc etc, he even dressed like sans as he saw him as a good teacher and friend, and also learned a few puns, he became like sans, much to papyrus' annoyance, eventually, clone tails learned an ability of his own: universe travel, so he was able to go back to his own, as well as return to the UT universe at any time, by the time he was finally able to return to fnas' universe, he was a completely diffrent person, the other clones were intrested in undertale's timeline, so clone tails took them for a visit once, they couldn't learn abilities from other characters there however, only tails could, sans and papyrus remained good friends with tails, and he often visited them, as well as being able to be called into the UT universe in the case he was needed for an emergency

facts about him

tails' personality is similar to sans' but he usually jokes around less on emergency situlations, but thats not to say he doesn't, and he'll usually hold back less, so his attacks are usually harder than sans' and he will absolutely destroy you if you harm sans or his friends

Tails' power is about 5X higher than Sans' and holding back less, this means that messing with him is a really bad idea, he can also use both colored attacks, and also learned to use the rest of the soul modes from other monsters, so he can use more than blue and red, in addition to these, it also takes a long time for him to get tired, so he can fight for long peroids

he'll initially try to become friends with you, but isnt holding back as much as papyrus, so you'll really wanna make sure to get on his good side

Tails isn't affected by true resets, so trying to make him forget something isn't really an option

Tails can use green attacks to heal his friends and himself in battle, this includes all of his arsenal, bones, blasters, etc

Tails takes 5 hits to kill, regardless of how much damage he takes from an attack, but he'll only tolerate up to 3 before he goes full power

Tails can also time travel, so he has seen how he'll become in the future, but knows how to prevent it, but the toys still play a role in fnas as he makes sure that they will exist, as he befriends them, and wants them to live their lives out, as he's aware that they do have their own minds, a thing that they hide from the rest of the world

Tails is best friends with Toy Tails, and even has feelings for her, but hides it very well, he only trusts Sans on it, who promised not to tell anyone despites hating to make promises, he doesn't wanna risk seeing the future to see if he will be with her as he is afraid of rejection, so he has modified his travel in a way that prevents him of seeing any future timeline where he admits his feelings, he is also afraid of how the others could react to him having feelings for a robot, and so hides it in any way possible, he doesn't even tell Sonic, who is like a brother to him, harming Toy Tails will warrant you an instant one-way ticket to hell

Tails loves bad puns as much as Sans does, but is bad at coming up with them, so Sans gave Tails a joke book to read in his free time

Tails has not regretted the attempt to make that portal since his meeting with Sans and Papyrus, as he loves how his life went since he met them

Tails has met the other monsters like Undyne, but prefers to be with the skelebros, thats not to say he dislikes the others, he's pretty much neutral with them, he's aware of how determination works, and regularly helps Alphys with it, even though she feels more nervous than usual when he's there, as he's another character that knows about the amalgamates

Tails's body can handle a lot more determination than Undyne, more than 20 times to be exact, before he starts having issues with it

Tails is usually very calm, and doesn't get scared easily, he also doesn't try to kill people unless they provoke him, but even then he only tries to injure them, and will not outright kill them unless they try to kill him or his friends first, as already mentioned, Toy Tails is an exception, as harming her enough will cause him to end you

he overall tries to befriend people, and is known and liked by everyone in the underground, unlike Sans, he'll try to stop you early, but he'll not attack fully until the last corridor, as he wants to hide his real strength from the others in the underground

Tails will try to use bones to block attacks, but will usually just dodge them instead

Tails has met Manic (@Manic0626 's oc) and is friends with him, he, Tails and Sans form the speed time trio, and if the situlation REALLY gets out of hand, they'll all fight together, which is usually not the case often, but when it is, they're a force to be reckoned with

Tails IS aware that toy tails could be turned into a normal mobian/clone with the master emerald, and he has asked her about it, she said that she'll think about it, which Tails understands

Tails does occacionally dress as swap!papyrus just to look diffrent (usually when his clothes are in the washer)

Tails has seen other fnas universes like nightfall at mario's, fnas redacted, etc etc, and is intrested with them, and will often spend his time watching them, but due to what could happen if he intervened at any part of them, he does not visit them

Tails has seen other AU sans-es, and hates evil ones like Fell!sans, Error!Sans, and others such as him, the only evil Sans he DOESN'T hate is Dust!Sans, because Tails understands he was left with no other choice

Tails likes to spend his free time drawing, during which he wears a special outfit he made (imagine him as INK!Sans) he even made a drawing of him and Toy Tails together, which he always has with him to make sure no one sees it

how Tails and Toy Tails could be together

note that this is not canon to Tails' story, its just how they COULD be together

remember that drawing Tails made?
once he was chatting with Toy Tails, and when he finally went about his way, it fell out of his pocket without him noticing, Toy Tails picked it up and was surprised when she saw it, then blushed realizing Tails made it, she'd seen his style before, so there was no doubt, later on, Tails went to grab the drawing to look at it, but started panicking when he realized it wasn't there, he run back to where he was chatting with Toy Tails, but she had already left with it, Tails was panicking a lot, even more later, Toy Tails was talking with the other toys about what she should do, revealing she felt the same in the process, Toy Sonic (somehow) suggested a smart and simple move: to just tell Tails the truth, so Toy Tails decided to do that, she eventually found him in his cove, and Tails immediatelly blushed hard when he realized she had the drawing, but Toy Tails explained she didn't just come to return it, but to admit how she felt too, Tails was a bit surprised she felt the same, but didn't care, as his dream had come true, both of their dreams did, im sure you can imagine what they did next (no they didn't do the UwU, they just kissed)