"'Mana,' like this world's Bios, is a form of magical energy. Also considered life energy -- again, akin to this 'Bios,' mana powers magecraft and spells. The great portion of mana comes from the World itself."

There were other distinctions, such as od, produced from the human body, and mana proper, originating from the world. Both were spiritual energy, though the latter was of greater concentration and power. But Gilgamesh thinks it is not really necessary, particularly for the sake of comparison, to go into all that.

"I was born during the Age of the Gods, in which the concentration of mana in the world was far greater than in later times."

He has already given such details to Lucy during their conversations. What Gilgamesh omitted then, as now, was that his actions had played a role in the downfall of that Age.

"It seems there is some similar ... force, or power, in many cosmologies. Yet I should wonder if these are all manifestations of some same origin power, or whether they are truly separate."

A theory of everything -- if all their worlds/universes were experiencing something of the same, but under different names. Yet that is only a hypothesis, though one he supposes a man such as Ratio might appreciate.