@Background Pony #B22A
That’s my theory as well, minus the familial connection. X3

Este es solo el Rey Sombra antes de caer al lado oscuro…Solo mi loca idea

Hace 1000 años. Celestia y Luna derrotaron al Rey Sombra y lo desterraron al “hielo del norte ártico”, pero no antes de que el Rey Sombra maldijera al Imperio de Cristal y lo enviara al futuro (1000 años). Cadence, Pegasus, que es la hija de Sombre, también fue enviada al futuro con el imperio. Pero ella cayó del viaje en el tiempo y apareció en Equestria antes de que el Imperio de Cristal vuelva a aparecer.

Ella perdió sus recuerdos y fue encontrada en el bosque por ponis terrestres, quienes la llevaron a su aldea. Cuando creció, revirtió un hechizo de robo de amor lanzado por un pony llamado Prismia. Prismia llevaba un collar potenciador de la magia que amplificaba su maldad y sus celos, pero cuando Cadance la confrontó, el collar amplificó el amor de Cadance. Una vez que Prismia cambió sus horribles costumbres, Cadance fue rodeada de energía mágica y transportada a un lugar extraño donde conoció a Celestia, quien la adoptó como su sobrina real. (De. Libro de hechizos del corazón de cristal)

ฺ Y sin recuerdo del pasado …. sin saberlo. Mató a su padre con el poder del Corazón de Cristal …

This is just King Sombra before falling to the dark side….Just my crazy idea

1000 year ago. Celestia and Luna defeated King Sombra and banished him to the “ice of the arctic north”, but not before King Sombra cursed the Crystal Empire and send it to the future(1000 year). Cadence, Pegasus who is Sombre’s daughter was send to the future with the empire too. But she fallen from the time travel and appeared in Equestria before the Chrystal Empire appears again.

She lost her memories and was found in the woods by Earth ponies, who took her to their village. When she grew up she reversed a love-stealing spell cast by a pony called Prismia. Prismia wore a magic-enhancing necklace that amplified her evil and jealousy, but when Cadance confronted her, the necklace amplified Cadance’s love. Once Prismia changed her horrible ways, Cadance was surrounded by magical energy and transported to a strange place where she met Celestia, who adopted her as her royal niece. (From. Crystal Heart Spell Book)

ฺAnd with no memory of the past …. without knowing it. She killed her father with the power of the Crystal Heart …..

Rey Sombra: Cariño, tengo un pueblo al que subyugar. Ve a jugar con tu madre.
Princesa Cadance: La arrojaste a la calabozo.
Rey Sombra: Lo sé.

Cute

His appearance reminds me of rick Sanchez

Dawwwwwwwwwwww^

Sombra: Do i look like your fucking daddy?

uhhhhhhhhhhhhhh wat???

@Vocal  
Headcanon considered.

I like to think that King Sombra was good, once.  
I’d like to think that the Crystal Heart is the embodiment of all his love for the ponies of his kingdom. He had to put all of his love into an artifact that saved the kingdom by driving something away, but he did not realize what that would do to him, and he desperately tried to keep Cadence from knowing the truth behind the crystal heart. Just hat he wanted her to keep it safe. (Or he knew very well, and tried to keep himself in check, but then he got out of control.)
 
….And now, in “That Box” is the way to restore King Sombra to being not only alive, but good. And then Sombra and Cadence will have a tear-filled reunion when she recognizes him as her father.

Headcanon’d :D

@romantiCaveman  
I like to think she was cast into suspended animation for a few centuries, probably by her father so she wouldn’t see what he became. I don’t think her origin ever says how long ago she ascended, only that she did.

@Evowizard25  
Yeah, Cadance could’ve been in a similar 1000-year stasis like Sombra, just not as long-lasting.
 
I particularly like this headcanon because it allows Sombra to come off as even more of a monster: in addition to being an evil overlord, why not add “horrible father” to his list of atrocities?

“Daddy, will you read me a story?”  
“Who the hell are you?”  
“*whimpers*”
 
@Evowizard25  
Headcanon considered.

@Evowizard25  
Always two there are, a master and an apprentice. Watch your freakin’ back, Cady.

You know, I always played with the idea that Sombra was Cadance’s father before he became corrupted. It was easily fit with what we know of her backstory.
 
@FanOfMostEverything  
It’s stuff like that, that leads to her taking over the kingdom. {He would be so proud.}

@FanOfMostEverything  
kek

“For the last time, I am not your father. I was just the Crystal Queen’s admirer and lover one time before she selfishly broke my heart! She married her husband as she was already with foal and- … wait a minute.”

“Darling, I have a people to subjugate. Go play with your mother.”  
“You threw her in the dungeon.”  
“I know.”