Capítulo 1743: Unconditional Faith.

This is not her natural strength. Axec was at level 44 when they told Warshaw to choose her. It was their blessing that improved her so much and grated her access to Mana. That access to Mana is why they are confident that she will beat every challenger tomorrow. 

She doesn't have a class yet, which means she won't be able to use mana techniques and skills. But just the natural endowment of mana will help her heal and recover her stamina faster. 

The council members are older and so are more skilled. But they don't have mana. That means they won't have the replenishment of stamina and the boost to power that mana grants. If that boost increases to 10% in the two days they have, Axec will have another edge over her challengers. 

Sure, it would have been better to choose one of the council members as their champion, but they didn't do that because strength is not the priority. Faith and obedience to the gods are the priorities.