Aurora, Lyra
"Oh it's fairly simple procedure," Aurora said, "Not easy. But simple nonetheless. Preach about the greatness of your god, carry out their rites, and if necessary offer a demonstration of their power to the more vehement infid-er... non-believers, using what powers you've been bestowed. Or by asking for a miracle from them. Sometimes you'll have to get a bit more hands on than that and tackle a person's or community's plight in the name of your god. If you're successful and avoid too much collateral, that typically goes a far way towards ingratiating the populace and making them more open to entering the fold. Mortals tend to be drawn to heroism, after all. Especially that sponsored by a deity or other great figure."
The diminutive queen began pacing around Lyra and, it seemed, using the opportunity to examine her even further. "Then of course, there's terror, and indoctrination, which I've always found worked quite well when properly executed. Indoctrination is fairly self-expanding and easy to maintain so long as one keeps up appearances. Terror serves as a valuable weapon against non-believers who might oppose you, and a coaxing tool for those on the fence about whether they want to commit; after all, better to have a god as a patron than an enemy, when you're a mortal. But I don't believe that Mitsurugi is the type to endorse those latter two methods, so we'll largely be refraining from them."
Having made one full pass around the mercenary, she stopped on a dime and stared the woman in the eye. With so close a view, it was easy to see now that whoever or whatever this spider lady was, there were no whites to her eyes. They were unending seas of verdant green, not unlike an expanse of rolling steppes in mid-spring. There was something undeniably inhuman about them, but what exactly would be Lyra's guess.
"Regardless of the approach, however, the first step to successful conversion is to know one's god. So for now, you and this 'Kraken' should do what you can to learn from Mitsurugi. How she expects her followers to conduct themselves, what she represents and how best to honor her domain through rites, rituals, etc. In short, you're going to have to become priests. Or something very close to it. While a screaming missionary with nothing but a copy of scripture and holy symbol but no actual ordination or blessings can bring in more followers, it tends to be hit or miss, depending on how good their rhetoric is. But that's all it is to non-believers if it doesn't work, failed rhetoric. Priests are able to actually back up their claims, among other things."