Extra ideas that are more speculative:
- Lelouch can give the Anti-Spiral a geass power
Lelouch gains the ability to spread geass to whoever he chooses. If he wanted, he could give a power to AS. Why do this? Perhaps Lelouch gives him a power that has a heavy side-effect, or one that can somehow disrupt AS' natural abilities. Even something that distracts him for a little bit can be helpful. CC could also control geass users to some vague extent, Lelouch may be able to do the same here
- NoN Lelouch has CG Lelouch's powers, and more
With strong connections of alternate realities and such to NoN, plus CC herself being so connected to them and Eden Vital, it's not a huge leap to consider the various CCs of the different Code Geass universes being similar enough to share powers. Therefore, as inheritor of CC's abilities Lelouch would gain the geass powers of those other universes, including CG Lelouch's power of Absolute Obedience. Taking this notion of alternate universe powers even further, this would mean Lelouch could have abilities from other CG stories. These powers would include powers like Bless (force own thoughts into others) and a form of Absolute Obedience that relies upon voice instead of eye contact.
NoN Lelouch could also have CC's ability "to be loved", basically he can make anyone he wants fall in love with him. So we'll see how much the AS hates humans after Lelouch gets him under his spell heh heh he'll get some spiral power in him if you know what i mean
It's also not a huge leap to assume that perhaps NoN Lelouch already has such abilities thanks to becoming the Black King, and it was simply never given out to anyone. This sort of talk leads down a dark road of "well NoN Leouch can have any power he wants now", which is not a great place to go. But it's still a thought to bring up.
--
Currently playing: League of Legends, Chrono Cross.
Current Projects: Fool's Overture, CYOA: http://www.gamefaqs.com/boards/8-gamefaqs-contests/60143513