Part 1, "Draw Oculon Energy to Refractor Unum":
Clear the random mobs around the area. In the middle of the platform there is a non targetable mob called "Oculon of Storms" - stand near this and let it shoot it's blue crap at you, you won't take damage. Then run to one of the three spires along the outer edge, and keep doing it til each has 30 charges.
Part 2: Click on the blue canisters in front of each of the 3 spires
Part 3: Kill
Part 4: The non targetable Oculon is now targetable, kill it.
Part 5: Eat cake, you deserve it.