Mage/Dark Wizard Quetzalcoatl build

Currently I use this build: #CN0W9WZF8t2uQmKEcoXjEQdGFkTSvzRclnqV1 (This is wynnbuilder link, the part after)
Dune Storm / Echoes of the Lost / Sagittarius / Revenant
Ingress / Ingress / Lachesism / Contrast
Main weapon Quetzalcoatl, offhand Predposledni for cheap teleport.

I also have an option by using Brainwash as helmet, which has an increase in damage, but brings bad spell cost cuz it has -46 INT, esp. teleport for with that I cannot use Predposledni.

I am preparing for a try in Legendary Island, so I cannot use LI related stuff. I also cannot afford a new mythic and do not want to cuz Fruma is near.

Any other advice is welcomed.