Gaianan Crusade

Step 1: Drum up support - get the Sector on side, convince/ridicule/blackmail/denounce/burn those who disagree, acquire lots of military backing

Step 2: Preparations - muster the forces, establish Drakon V as the first of the Gaianan Sentinel Worlds

Step 3: Crusaaaaaaade!

Step 1: Get backing
As we find ourselves in the Kronus system and suddenly filling the shoes of a Living Saint, we may as well win the planetary war for the PR value.

Once we've kicked ass in Kronus, we can probably justify nicking off with the cream of the troops. Tethys siege regiments, Prometheus tankers, any Knights or similar quasi-independent forces who want to go a-crusading, etc.

Then we can journey on to rendezvous with von Holstein, secure our place as key leaders of the Crusade, and use that prestige to build up military forces under our direct control.

At some point we need to visit High Khessar. Possibly visit Voidsquall Station first.

Step 2: Groundwork
Leave von Holstein and friends crusading across the Correndor sub while we jet around preparing for the greater crusade in the Gaianan Stretch, intermittently delivering our forces to support the Correndor crusade (getting them experience as a bonus).

Continue establishing the Drakon system as the de facto capital and staging point in the Gaianan Stretch. Get the various Imperial institutions involved using the connections laid down in step 1.

Step 3: CRUSADE
Take our battlefleet and ground forces, those of Holstein, and assorted Imperial forces; go bring key worlds of the Gaianan Stretch under the Imperium's control, fortify our conquests, and eventually push on through the stable warp rift.