I should hope so, I wouldn't feel safe sleeping on top of such a large mass of mana if it was completely uncontrolled, but you'll have to ask somebody who knows better.

[ Assassin's just a farmer-turned-wanderer-turned-samurai hero, Saber. He knows a surprising amount about a lot of things, but how to deal with huge stores of mana is definitely not in his wheelhouse. ]

I would never wish to see Caster again, but that vixen would know something about this. If nothing else, she would find an excuse to use up all the mana here for something or another.

[ Like making a million Saber figurines or something. ]