User blog comment:KnocknickKnock/How Second Origin Really works?/@comment-10058473-20140225054609

Second origin is not a second container, but actually part of the container that *normally* does not get used. (The image explaining it might be somewhat misleading into showing two containers, but the explanation explicitly mentions second origin as part of the same container)

It's possible that this energy is only accessed in extreme cases such as life/death situations allowing one to survive or fight in conditions that normally wouldn't be possible to do so.

Easier access to this second origin is likely gained over time. After all a spell that manipulates time is what was used to unlock the second origin, so essentially what happened is that the container of those exposed to the spell was moved forward in time to be able to use the second origin.

This makes sense as it would explain why older/experienced mages can last longer in battle and also perform more powerful spells, which essentially is what happens when second origin is unlocked.

My point is, unlocking the second origin doesn't necessarily double their magic power. The improvement gained off it is likely to vary depending on each person, based on the amount of magic power available normally and on the amount of magic power in their second origin.