Some information I found off Lore AMA 2013:
" Q) What was going to be the plan for the final incarnate powers and trials? (@Sarrona)
A) There was no “final”, once Omega slot was reached that would be the new “Alpha” slot and 10 more Incarnate levels would appear above it. Getting the first 10 Incarnate powers would have been trivialized so the “new grind” would be the Omega-base tree. And then there was a tree after that, and one after that, etc. (Matt)
Q.) Do you have any insight as to what the Omega Incarnate Slot might be? The others seemed badass enough already. PBAoE kill everything?
A.) Jeff Hamilton would know. I don’t remember if this was Omega or not, but I know one of the latter tiers did allow you to nuke minions through your magnificence. There were also abilities that let you trade off one stat for another. (Hosun)
A) I’ve said this in a couple places but the primary trees which had been sketched out on paper were Arete (instant recharge on all powers for a period), Majesty (cause foes to instantly fight for you and then self-destruct), Infinity (summon doppelgangers of yourself), Transcendence (immune to everything and can attack into Phase), and Fulfillment (major PBAOE +Level Shifts) (Tim)"
The full doc: https://docs.google.com/document/d/11bjjR2rdP9Kbe8baODElUQGRxNTTlj_b5PVqCdNXJ8o/edit
These powers sounded really cool, especially Infinity (which I would have absolutely LOVED on my Ill/Time). Though, I wonder how content would have been like as the scale of Incarnate powers increased. After Battalion, there would have been Dimensionless and possibly True Rikti and Primordials, so maybe launching out into space zones?