She was the last queen of the Eth, Tyviel the queen who sealed the secrets and hid it from the invading planes. What she sealed were not something normal, it was the last great construct of time. It could shift in, out and even stop the time all it needed was the mother planarite from the planes.
After Regulos fall everyone shivered of fear of what could happen next, they couldn't imagine much greater fears, deep under the lost Eth empire something was awekening. Tyvial's task was complete the mother planarite have been taken too the guardian and defients keepings and all she need is them. She started the second great war against the guardian and defiant forces.

Come up with details in lore, i'm not a lore fan but i ahve just thought of this. You know her liutentants different characters constructs.

She walked down the great stairs of the infinity gate, her prophecy was complete and she now had the power of time and the planar forces. The souls of the old dragon gods saw her beuty and bew to her. Her dress were flying of the great winds clapping from the ocean, now Telara will fall she screams.

Now the last encounter of the expansion start and it is just epic!