Dude, when it comes to theories about the Dragon Prince, I'm torn when it comes to the half-elf Callum theory, because on one hand, Callum being fully human would mean that he is proof that humans can learn how to do primal magic if they work hard enough, making him an important symbol of peace on both sides.... But on the other... Callum being half-elf would make him a symbol that even in the Darkest of Times, love was found, and he is a direct result of that love which also makes him a symbol of peace for both sides, and even if he is only half, that doesn't take away the amount of work and determination he made to get to the place no human has gone before. (still, I find it a bit odd he connected to the Sky Arcanum quick as he did only a few days after he broke the Primal Stone since according to the timeline, it had only been two weeks in the second season. Of course, it could also be that they ran out of time since there weren't that many episodes)