Unbroken Host

The regular military of the Heavens, tasked with combating the numerous enemies of the faithful in the Material Worlds - it is intentionally kept weak enough to be able to operate freely there, while still being a force to be reckoned with (even if they end up deploying in the Spiritual Worlds, although there they are more of a cannonfodder there, even if respected and technically immortal).
The Unbroken Host is composed primarily of the Dead - either former soldiers or those that ‘joined the army’ voluntarily after their deaths. Their experience as mortals does give them a bit of an edge when operating in Material Worlds - they better understand the limitations and emotions of those they typically end up fighting alongside (and sometimes against).
They are divided into armies, which are then divided into divisions. Each army and division commander is a famous mortal commander (someone like Alexander the Great would count as an army commander material). Those commanders are greatly boosted with the powers of the Bellaminae, the twin Exarch of War that acts as a commander-in-chief of the Unbroken Host - the army commander has a decent chance of slaying a titan-grade enemy (although while accompanied by their personal retinue of soldiers - they are powerful, but their power lies mostly in teamwork).
The greatest strengths of the Unbroken Host is its versatility and refusal to yield in any circumstances. You can expect the Host deployed divisions fitting the circumstances perfectly - so for example a cavalry unit on open plains, or some mountaineers when in mountains. With the equipment of wonderful quality produced by the craftsmen serving the Exarch of Industry, even former guerillas will be turned into dangerous combatants.
Then comes the unyielding part. The armies of the Host cannot die - only be banished back into their strongholds in the Spiritual Worlds (most of them are Shard Worlds, though). As a result, they never retreat from the battlefield and have to be slaughtered to the last to be defeated. This makes them incredibly dangerous, simply because normally the standard form of victory in battle is to force your enemy to retreat after slaying a fraction of their numbers.