Eden Vital seems like a hard counter to Anti-Spiral's biggest trick, locking the opponent away in an alternate reality. I definitely buy Lelouch being able to break free of that -- particularly since Eden Vital is apparently passive and would alert him to the nature of the universe even if he didn't personally realize what happened.
It's the rest of the fight that I'm not entirely sure of.
Questions about Lelouch:
- Is it ever possible to defeat him, by any means?
- Is his regeneration/revival instant, or how long does it take? (Has this ever been shown? He is apparently invincible, after all.)
I will say that the Lelouch arguments have been far better, from the perspective of someone who only watched ~8 eps of TTGL before quitting the show, and never watched any of Code Geass. Anti-Spiral supposedly being on a different level of power is not that convincing if he has a tendency to fight opponents on their level.
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another place and time, without a great divide, and we could be flying deadly high