<p>Hi LPXM, good luck in your project, I strongly recommend read the light novel, buy it it's a way, borrow it from a friend is other, the others aren't legal and I don't give you a hint, is better support the original work, but a ebook versión is cheaper than a printed one.
</p><p>My advices for you:
</p><p>-read all you can (danmachi, sword oratoria, family chronicles, sides stories, specials...)
-Try to avoid all "friction" with the original work, this things don't end very well
-The author used gods of norse, greek/roman, egyptian, mesopotamian, irish, hindu, japanise, but (for now) he don't use gods from mayan, aztec, incan, persian, (and maybe others, but I don't know others cultures that have gods and no spirits), using one of this, put your work far from the original.
-if you work go slowly, don't care, all the starts are dificult, and is better a good work than a fast one
-be constant
-be patien and never lose your ilusion in the work
</p><p>if you say more about you want to do (like if the game it's from the point of view of a god or an adventurer, a incipient familia or a existing one, and more things) we can try to say less general things
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