So I have finished the troll quest and have recieved the book to allow me to carry tenebrium and weild tenebrium weapons, now I have a weapon that requires tenebrium 2 to weild, I've seen many forums asking if increasing tenebrium level is worth it, but none that say where this tenebrium skill is and how to increase it.. as I've looked through every option in skills and attributes/ whatnot, and I do not see a way to increase my tenebrium skill anywhere, please help