Boundary Wards

Sometimes things go really bad, resulting in Abyssal terrors coming into an area of Bal-Kriav, like what happened at Turgon, or perhaps someone made a mistake in the lab and unleashed some nether terror upon the populace, like what happened at Frosvir, or some careless mages decide to create two fell thrones and then unleash elemental forces upon each other, like what happened in Elemantum.    For these types of events that threaten a large area or perhaps even an entire continent, no small ward will suffice, arcanists have to bring out the big guns, and its not just one wizard, but many that are required to produce containment fields called boundary wards.  The biggest of these cover entire regions.

The Elemantum Boundary Ward confines parts of Elemantum, for without it, brutes of fire and ice are gonna run amok.  The Maen Fyrk Boundary Ward was created to keep negative energy from further corrupting the lands around Frosvir.   The Turgon Boundary Ward was erected to keep the hordes of the Abyss and the meddling of Demogorgon from affecting Bal-Kriav.

... and if you think a shield coming down is a joke.