Capítulo 915: The Totem.

He has seen enough of the Warrogs to know that they don't have spell legacies. They haven't studied the intricate control of mana. Their society is still at the tribalistic stage. He decided to use a spell to impress the old Warrog. It seems he was right.

Most races that delve into spell crafting have a large population of Mana entities. Mana entities are close enough to Mana and can perceive it better to know that it can be used for much more than strengthening the body. They will then make research into magic to strengthen the soul which will also benefit Vitality core stage refiners. 

Vitality core refiners have limited lifespan, Mana perception, and spiritual resources to create spells. They are like the Shaman here. They will get old before they can make meaningful progress in the development of spells. This becomes doubly difficult if they don't have a written language and a method of knowledge preservation.