Breeding for moves that a Pokemon can't get otherwise.

[Velah]

So I'm trying to figure out if there's a way for me to get a certain move, (two moves, actually) onto a Kirlia. I'm trying to replicate a Pokemon that I used in an RP a loooooong time ago, in which my Kirlia, (A shiny, nicknamed Key) ended up learning Dragonbreath and Psycho Cut through supernatural means. My question is this, basically: Is there any legitimate way to teach a Kirlia Dragonbreath and Psycho Cut? I would presume that, if there WERE a way to do it, it'd be with breeding, but I'd have no idea how to do it. Can anyone shed some light on the matter?

And if it's totally impossible in the games, we might as well discuss a hypothetical situation in which it would be possible.

 

[Dr. Silver]

It is impossible to get these moves onto a Kirlia as far as I'm aware. Though, Gallade can learn Psycho Cut, but that might be due to it having bladed arms.

Even if we take hypothetical situations into account, there are no Pokemon within Kirlia's Egg Group at all that can learn Dragon Breath. If we gave Pokemon in the Egg Group the opportunity to pass down Dragon Breath, the only two Pokemon families it would make sense to learn it are the Slugma Family and the Eelektrik family.

 

[Velah]

I could definitely see Slugma-kin being able to learn it, especially considering the Gen 3 animation for the move being a simple recolor of Flamethrower. As for Psycho Cut, it'd be nice if Gallade could pass it down...

I figure that while I'm mentioning it, I could explain exactly what the story behind "Dragon Key" is.

Basically, in the RP I played an assassin character whose main Pokemon was a shiny Kirlia named Key. She knew Psycho Cut from the beginning due to her training. Key had a story arc in which she began having a recurring dream, where a Gardevoir would tell her things, warning her of coming dangers. This was basically my implement for foreshadowing how I planned to direct the plot. In these dreams, Gardevoir would come to warn Key about the demise of one of my character's other Pokemon, a Flygon who had become corrupted by the Shadow plague. Key acted behind my character's back to attempt to hasten Flygon's purification, but was tricked by one of the villains. He had given her an item, claiming that it would accelerate Flygon's recovery, but it only re-corrupted him, and during a crucial battle later in the story, he began to lose control. My character was unable to recall him to his Pokeball, and was forced to collapse a section of a building on him before he injured several allies. Key became a conduit for Flygon's corruption due to something the villain had done, and inherited several of his abilities, including Dragonbreath, which she would later use to fight Shadow Giratina.

As for why Giratina was corrupted, the villain did so for basically the same reason that the villain of Gale of Darkness corrupted Lugia. He had forced Kirlia to learn Dragonbreath as a way of gaining an advantage against Giratina, although he ultimately failed when Kirlia chose to kill it instead of merely KO'ing it.

The main gist, though, is that I really want to have "Dragon Key," (as Key eventually came to be referred to) in an actual Pokemon game. I think I might just write a script for a fangame adaptation of the aforementioned RP, and hope that gets me somewhere.