First Referenced:
The Desolate Guardians (Part 4)
Additional References:
The Desolate Guardians (Part 5)
'I was told that everyone I'd served with in the military died shortly after I left.'
The Outer Shield is a vast structure, encompassing many different realities that are (or were) populated by humans. The Outer Shield requires constant monitoring and maintenance to ensure its stability, otherwise cracks and rifts can form which allow dangerous entities to enter human populated universes. This maintenance is the responsibility of Command, which appears to have abandoned its task for reasons unknown. As a result, the Outer Shield has cracked in numerous places, allowing Sentient Flames to enter, along with innumerable malicious entities.
The Outer Shield, along with the Inner Shield and Branch Worlds were constructed with the assistance of the Brownshirts, who assisted The First World when it was a new power in the multiverse.