As for maintaining Irea's citizens' trust in the Phoenix Legion when the entire Chapter left the system to fight in the 12th Black Crusade, I thought of Chapter serfs left behind to maintain the fortress-monastery on Irea III, as well as Chapter keeps on IV, V, VI, and VIII, coordinating with the planets' governments to maintain human control over the planets- though I expect in at least one case, the serfs had to kill a planetary governor who's a genestealer hybrid. The serfs are forced to raise militias to fight the xeno-tainted heretics, and eventually, the latter's Purestrain masters; breaking into the fortress-monastery and Chapter keeps' armories to distribute weapons to the militia members; act like religious demagogues to maintain the militia members' faith in the Emperor and "Trust in His Immortal Majesty's chosen servants, the Phoenix Legion, who will return once the archenemy to all mankind, Abaddon the Despoiler, is defeated." (The serfs know breaking into the armories was a capital offense, but "Needs must when devils ride," and they expected to die in battle long before the Marines could return to punish them.) Without starships, serfs on one planet couldn't aid those on others; but the fortress-monastery and the Chapter keeps served as shelters for untainted citizens when the Ordo Xenos enacted the Blight to wipe out Genestealers on the planetary surfaces. (Again, the serfs committed a capital offense in the latter, as they had no authority to let people into the fortress-monastery and Chapter keeps; but the forts' security systems could scan for xeno-taint, allowing the serfs to ensure they're not letting Genestealer hybrids into their masters' domains. Once they saved as many as they could, the serfs marched out the fortress-monastery and Chapter keeps, sealing the gates behind them, to fight the approaching mobs of panicking people and possible Genestealer infiltrators, and die in the subsequent igniting of the atmospheres, punishing themselves for their crimes.)
I'm going to extrapolate on something like this when I get into chapter history. I've decided on using the invasion of hive fleet Behemoth and specifically the battle of Macragge as the instance to pull the chapter away. Turns out it included a major force of warships from Segmentum Tempestus so it's not very far-fetched that they would be included in the reinforcements.
My next steps are going to be including "rebuilding trust" sections and then finishing up chapter organization.
Thanks again for your input it's been a big help.
Edited by FoxLGV, 13 September 2019 - 01:25 AM.