As it has been awhile since my last character became a priest, I recalled what my priestess character did back then sometime ago. Hopefully it not changed that much since then.
My priestess character went and preached to the rogue region.
1) Gain majority followers in the region.
2) Calm the population.
3) Laud the realm. Obviously having the rogue region people hateful to your realm will not work for RTO. If people are hateful, the less chance they will join your realm.
4) No monsters and undead around or any armed troops.
