No, logically speaking what Brian did was completely out of blind love. Dragons can't massacre humans therefore if Sol was gonna defend the country, they will need resources and man power. What's going on in Brian's head was probably that he won't be able to live forever but he wants to protect Sol and his country even after death. Of course it is still wrong that Brian isn't communicating this with Sol nor respected Sol's wishes. But I think it shows how much Brian loves Sol. To protect him with his life and make sure his future is smooth sailing even if it costs Brian's life.
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Was it love or self-satisfaction? For sure he is using love as an excuse to do whatever he feels like without taking into account anyones feelings or consequences.
Brian is actually the selfish one if you think about it he's cosplaying that selfless stubborn shounen protag outfit and saying stuff like I'm doing this all for youuuuu ughhh bro bfr sol has never once asked you to dominate the world for his sake at the end of the day it's your own wish to do that and he's using sol as an excuse to continue forward with his reckless actions