Abstinence from having sex

"Now that your whole harem is here, do you feel like having sex with all of us right now?"

Silence. 

The entire room turned silent just as Lilith finished speaking this. They couldn't believe what they had just heard. The revered Vampire Queen just said what to her son!?

Lith chuckled hearing this question and said, "I would love to, mom. But time is of essence and I need to cultivate."

Lith wanted to be Rank 9 as soon as he could. At Rank 6, Lith's lifespan, which was already very long, would become even longer and he would partially leave the mortal realms. He won't need to have food for sustenance as from Rank 6 onwards his body would use the elemental energies to nourish itself and grow.

No major changes happen before and after Rank 6 until Rank 9. At Rank 9, one is close to leaving the mortal realms fully and finally venturing towards immortal realms. The body undergoes a qualitative change and that's about it that happens in Rank 9 as well.