To harm a titan, we need a weapon from the Plane of Earth. That's why I had you collect the Magmite Shards - so I could extract Elemental Ore. Take it with you to Sylver Valis in Meridian. Of anyone, he'll know how to transform it into a weapon.
This Charged Elementite you've created is an impressive distillation of Earth essence. It's much denser than iron or steel. Can you sense the way it calls out to its plane of origin? There are beings there that can sense it as well.