For Sebastian, Kremeth was everything.
When he was at his lowest point in life having lost his body, his confidence and his ability as a warrior, Kremeth took him in as a disciple and groomed him into the man that he was today.
He wasn't as talented as Max, he wasn't as sharp as Anna nor was he as ferocious as Asiva.
His greatest strength was that nobody took him seriously and hence he was able to get along with anyone he wanted to, afterall who would make enemies out of a jester?
However, despite all his short comings his master chose to hand over to him the Vayu-Astra, his most prized possession when he himself needed it more, just to ensure that despite his short comings he could continue standing shoulder-to-shoulder with the rest of his comrades.
For Sebastian who had grown up without the love of a father, these actions meant the world.
