Talk:Demonic Energy/@comment-28144855-20170208224258/@comment-10429980-20181209143359

World Guide 3 has explained all this in some detail. Namely that mana in an unaltered state indeed has no mass. Magic is partly defined by using one's will/imagination to alter mana into a different state that has mass and can be used to accomplish various tasks.

Presumably the black goo form that demonic energy can take, is simply a application of magic to give monster mana form, and condensing the energy beforehand makes this easier. In this way monsters like khepri can store it in a tangible form that stays in one place for long periods instead of dissipating, like a specialized use of the mana marker spell. We may learn more once the "dark matter" spell article is translated.

As for how one can change a vague energy into a physical state, well they don't call it "magic" for nothing. That said, the mental side of it can't be understated, magic in the MGE is partly defined as the ability to basically bend reality using one's own mind/imagination, with mana as the fuel source.

Relevant quote:

However, since that which we call mana originally has no mass or attack power, and it's basically just striking a foe with mana, it doesn't have much power at all, although some kinds of mana such as mamono mana have the property of exhibiting an effect even just by pouring it inside the target's body.

'''For that reason, when using mana as an attack spell, the usual process taken is to materialize it into something that has mass and attack power and manipulate that. We can say that spells that conjure and launch fireballs and spells that shoot icicles as lances, and so on, are all derived from “mana shot”.'''