Castiel was the first hatched of two eggs, an entire week before the second one. While him being first assisted in his parents having an obvious preference, another layer was added on after his sibling turned out to not be the anticipated togepi/eevee fusion. He grew up being treated like royalty, his parents and original trainer showering him with love and affection, as well as teaching him how they expected him to behave, prim and proper.

While he grew up not having an entirely bad opinion of his sibling, even caring for her atleast alittle, he still carried his parents outlook on her. This outlook made him tend to ignore them, sometimes even making fun of Pixie if not flat out putting them down over how they should've just hatched like him, a perfect fusion, like their family wanted.

When he got older, his family all went on a vacation to the snowy mountains, partly to train, to help get Castiel to evolve, his trainer thinking the eevee half becoming glaceon was fitting and would sell well. During the second day of training, he had evolved finally, him and his family started to head back to the cabin, right as a blizzard started to form. He couldn't see anything through the flurry of slush and snow, but he could feel his mothers ribbon grip onto his paw. He had heard a yell through the harsh winds, but was unable to make out what it said or who it was.

In just over half an hour, Castiel and his family reached their cabin and hurried inside out of the cold. As the newly evolved 'mon looked around at everyone inside the cabin, catching their breath, he noticed a fluffy form missing. "Where's Pixie..?" he asked unsure, not knowing how he should feel of the lack of the small eevee anywhere. His parents glanced at eachother before his mother seemed paniced. "Where IS Pixie?? We need to go find her!! We can't do it till morning however.. not in this weather." While this response seemed abit iffy to Castiel, if not at least fake, he wasn't too pressed to push on with the questioning and was satisfied with that answer. Of course, why would we go back out there and risk all of our lives? They'll be fine anyway.

The next morning Castiel awoke to his parents nudging him awake. They looked at him with sorrowed filled eyes.. or at least, faked sorrow. "Honey.. We found Pixie.. She was dead.. I'm sorry dear." He jumped up, surprised and semi hurt by the news. The family only seemed to mourn her "death" for a short time, though Castiel was more off-put by it than the others seemed to be, he didn't focus on that for too long as he was now getting his parents completely undivided love an attention. Not that he had to fight for it before, but he didn't mind not having Pixie take up their time with their general existance. Though he had overheard his mother talking once about how she just let Pixie go, seeing the opportunity Arceus "had so generously given us".

As Castiel grew older, his trainer sold him off to another. He was sad of leaving his parents, but was excited to be out on his own, even if it ment dealing with this *thing* trying to boss him around. They tried to get Castiel to be affectionate towards them, trying to pet him, give him treats, but he wasn't having it, not from this persons hands. He'd walk away as soon as they reached out to him, wouldn't take food unless they had left it somewhere for him and weren't around to taint the area. Eventually his trainer attempted to get him to battle, but Castiel chose not to listen. Using moves he thought were better, listening only to orders that he agreed made sense. Sometimes even choosing not to participate at all, and instead do something on his own, not paying any mind to the trainer.

The trainer eventually had enough, if he wasn't going to listen to any of their orders, and wouldn't even let them show him attention of any kind, ever, they didn't want to deal with him. They brought him to Aether to ask them to help him learn to deal with others better. Wanting him to go to a good home after being trained, even if that home wasn't going to be with them.