Su Mo refused the idea of possessing the physical body of the purple youthful and entering the Sun Moon Tribe. It was not a feasible idea.
After which, he pondered whether he would be able to find someone from the Sun Moon Tribe while possessing a body. However after a bit of consideration, he felt that it was not very likely.
First of all, the Su Moon Tribe was very powerful. The Sorcerer Tribe of Heavenly Underworld Star was no match for them. If he were to depend on possessing a physical body to enter the Sun Moon Tribe, there was a risk that he would be exposed.
Secondly, as he wanted to woo Qing Xuan, he would definitely be faced with a lot of competition from other Demonic Geniuses. However, once he possessed others, his strength would decrease greatly and he was worried that he would be of no threat to them.