I'll side with Oryx. I'll kill an ascendant, and assume command of his or her underlings. Ghosts can be destroyed in battle, so I'll swallow a worm instead as my form of immortality. Their tithing will give me access to all the light I need to eat to grow more powerful, and obviously Oryx gets a cut (Verse 3:9).
I'm already sharpened with sword logic, and shouldn't take long for me to get my own throne world and be officially recognized as a god and eventually branch out. I'll get some talented deathsingers, a beautiful oversoul, some nice totems here and there. I'll specialize in magic, but I'll also use a bladed spear and make it sharp through eons of use. Maybe me and Ir Anuk can celebrate Eversion Day together (Verse 4:11) by drinking bitter acids and turning beings inside out; she's nerdy with her study of the 11 axioms of the ascendant places, and I like that. I'll be happy and satisfied knowing that I am helping the universe achieve it's Final Shape. I'll give the species I defeat a chance to accept the worm as their lord and savior if I think they're worthy, and foster the development of great magical technologies similar to how the Ir Halak and Ir Anuk created deathsongs, oversouls, and annihilator totems.
Why list Quria, why not just say Vex? Quria was just one Vex mind, and he wasn't the most powerful, or the highest ranked. I don't think one can really join the Vex even if they wanted. You're either a component of collective mind, or you're not. Maybe if we could somehow join the Network... but that's a bit of a stretch.
Cabal make the species they conquer join them as slaves, so that's unappealing. They're also pretty bland and underdeveloped.
The only hope the Fallen will ever have is to side with the City, so I'm not optimistic about Kings ever achieving anything. The Wolves and Skolas was the best chance the Fallen had and being something more than just pirates and scavengers. I really sympathize with them when I read Ghost Fragment: Fallen 3 (read it, it's sad and inspiring). Skolas should be up there instead.