Larian Studios Forums Divinity - Original Sin Divinity Original Sin - Help/Tips/Tricks Tenebrium - what, where, and how?

I handed over all the T-ore from the Troll cave to Brandon. However, my homestead is under attack and Zixzax told me I'd need T-Weapons to destroy the demons. Where do I get those weapons? I'm lvl 15, I have explored Hiberheim completely, but I haven't encountered a single T-Weapon. (Apart from the treant-wand.)