Making Champions Casters
To make a champion into a caster your sovereign must have researched the spell Imbue Champion. This spell cost no mana to cast but it permanently reduces the sovereign's base wisdom/essence by 3 points and raises the champions essence by 3 points. (Note: If you cast this onto a stack with multiple champions the game will randomly choose a champion to grant +3 essence to even one who can already cast spells.)
The Empire player starts with the spell imbue champion. It is the same as the kingdom version except that it transfers 4 essence from the sovereign to the champion.
Sovereign Children - Inherit Essence