My current 1,500 point list below. I also own 1 Wraith and a Lord with a Staff of Light.
This list did well against Guard in it's only outing thus far (tomorrow will be against something else), although I found I want more Scarabs, but not sure how to add them. What I am looking for is some ideas on what I can do to increase to 1,850 points without purchasing a new army (so no, drop those three Warrior units for Immortals). If I were to add more than three more Scarabs, I would need to drop or combine Destroyers. I am also think of a C'Tan with Lord of Fire and Withering Worldscape modeled to be the Deceiver with a Ghost Rider-esque head floating in the center of a lava eruption like
http://www.geo.mtu.edu/volcanoes/hazards/primer/images/volc-images/puuoo.jpg. That would be 220 points but leave me feeling like I should have taken perhaps more infantry like 10 Immortals or a Resurrection Ship (sorry, Ghost Ark) with some rearranging of the Warrior Squads. As it stands, I am mainly looking for ideas on where to go from here.
Overlord - Warscythe, Tachyon Arrow, Resurrection Orb, Phase Shifter
Royal Court - 2 Lords w/ Resurrection Orbs, 1 w/ Voidblade, 1 w/ Warscythe
Cryptek - Harbinger of Destruction w/ Solar Pulse
12 Warriors
12 Warriors
12 Warriors
5 Deathmarks
7 Scarabs
3 Destroyers
1 Heavy Destroyer
Annihilation Barge
2 Canoptek Spyders - Twin-linked Particle Beamers