Hon. Wargamers;
I just played a game in which I located and recruited 6 champions. When my imbue champion spell was researched, I then began to imbue each hero in turn. I imbued 5 hero's in this manner. When I lost my last bit of essence, I was unable to imbue my last hero. I leveled up for the first time in a battle with wolves. I was not able to use my experience point to increase my essence for my channeler. I did not have a wisdom/essence stat. When I tried to re-imbue my channeler with one of my 6 essence champions, the spell was grayed out.
I find this somewhat humorous.
Don't imbue your heroes with your last 3 essence.
Respectfully
Pleroma