1) It’s likely that Akamatsu meant for a Darkness-based power to become important, as the nature of Dark spells have been obscure ever since their introduction back in Volume 3, where the Lexicon literally says “we don’t know what Darkness spells do”.
2) On the other hand, the Light-element Magic Archer was explicitly said to be “pure destructive energy” in the Negima Bible. The entry immediately after – Dark-element Magic Archer – states that the Dark version ‘opposed’ the Light version, but its effects are unknown.
3) We’ve known since Volume 23 that Dark Magic, based on the primordial power of Darkness, is “the power to take in everything”.
4) Aside from Dark Magic, there have been very few Dark-based spells in the story: Magic Archer variant, Snowstorm of Darkness, and Hellfire of Purgatory – the latter two are combos using another element plus Dark, though it’s interesting to note that the Armament form derived from Hellfire of Purgatory also has an ‘energy drain’ effect.
5a) If “Dark” = “pulling in” (absorption), then would “Light” = “pushing out” (repulsion)?
5b) Dark Magic is generally used to absorb Mana and magic. Isn’t there something that does the opposite of that, ie. repulse/dispel Mana and magic – the ability foreshadowed since the first chapter, which we now know as Magic Cancel?
5c) Magic Cancel is supposed to be the power “to give life to, and end, the world”, which would contradict the above – but Magia Erebea itself is based around ‘death and rebirth’ (volume 27). Could both Light and Dark have dual natures, just like Asuna’s dualism (which I rambled about nearly a year ago)?
6a) Dunamis noted that Magia Erebea was “connected” to his Lord (the Lifemaker) – curiously different from what Fate said about Negi’s power of darkness being “doubtlessly the same” as his Lord’s (again, the Lifemaker). Although it’s hard to say if Dunamis had just phrased it strangely.
6b) Following his ‘rebirth’, Negi is now on the “grey path” – the middle ground between the two extremes of Dark and Light. But Dark and Light aren’t as different as they appear to be.
Food for thought?