Same problem here.
Also i manage to avoid the Imaculate geomancer agro and she became friendly.
So i was stuck with none of my heroes with Tenebrium skill, only the two compagnons get it.
I must kill the geomancer to get a book and give to an hero 1 point on Tenebrium. Unfortanely the other one still haven't it.
If the pacifist way is a valid option, refuse Brandon quest and became friend with the geomancer, the skill should be avaible by other way.
In fact this skill should not be link to a "optional" quest.
