His body cultivation is higher then his essence cultivation, meaning out of all three his essence cultivation is lowest, he might as well take one of the pheonix inheritances to make up for his weakness. I dont see why this is a “dumb” idea.
you know I was gunna slightly complain as I don't believe the mc is strong enough to be giving away immortal inheritances but it literally doesn't matter for him cuz he has a great inheritance for the one thing that matters which is his soul cultivation. so whatever go for it