Recover Egalin's Grimoire and bring it to Carendin Halgar in the Temple of the Damned.
It seems the consensus that you are ready to learn to summon a voidwalker.
A being created of the chaos that lies beyond, if you summon one but cannot control it, you will be torn asunder.
The first voidwalker was summoned by Egalin, and in his grimoire is the process explained.
Unfortunately, it was stolen from us by an agent of the Scarlet Crusade who has it secreted away in his base at a tower to the west. Bring it to me, and I will impart the knowledge to you.