Dimension is a magic construction far more potent than a Magus's Domain. It allows a mage to create a secondary layer around a targeted area and gain control over it. Anything that enters that Dimension will be subjected to the mercy of the mage that created it. Even a Sovereign-level mage would be unable to do a thing once trapped inside.
Nevertheless, Dimensions are not a sure-hit skill. For one thing, one needs time to cast it. From this, if another disrupts the casting of a Dimension, then it can be broken. Of course, it will depend on how the other party disrupts it. The most effective way is to directly attack the caster or counter it by casting another Dimension. However, once a Dimension is completed, the only way to counter it is if another mage successfully attacks it from the outside. Putting a crack in the Dimension veil can allow those trapped inside to escape.
