Poisoned Apple.

As he was packing, he thought about the invitation to study with the true sons and daughters in the inner academy. The invitation sounded tempting, but he wasn't willing to give up his future for it. 

Swearing fealty to the family means prioritizing the interests of the family in all things. It means always helping the family as long as he can and to the best of his ability. 

If he swears the path and leaves this place for a faraway land. If something unfortunate happens to the family when he is gone and they send a letter to inform him or he hears about it, he has to rush back to help if he can. 

The oath doesn't mean he will become a slave to the family, but it will shackle him to the cause of the family. 

They won't ask him to die for them, but they will surely ask him to protect some of them. If he dies when doing so, then that's just an unfortunate event for him.