Notes from author
First of all, I based the overall set off of the Style and Steel costume as it is my personal favorite.
Everything about this build is inspired by Serah's stats and of course Mog being able to transform into a swordbow. The low vitality is because Serah doesn't have much in terms of hp, combined with the low str and dex, because she's not meant for physical, but rather magic damage.
For those who really want to cosplay, I'll explain how you can paradigm shift. (Or rather, how you'll change play style in fights)
Commando - Switch to broadsword and just attack. Or if you're far enough away use the darkmoon bow, but you have to switch back to broadsword if you're opponent gets close enough.
Ravager - Switch to Darkmoon Bow, and swap out your broadsword for your pyromancy flame. Switch between GLB and fireballs as you see fit.
Sentinal - Wouldn't recommend it, but here's how. Taunt your target with gestures, and turtle/ dodge (Dodging is allowed because Dark Souls)
Saboteur - Poison throwing knives and Lloyd's to simulate wounding. You could swap out for pretty much anything else that acts the same because Serah is a surprisingly good sab
Synergist - Green Blossoms, that's it.
Medic - Serah's not that good of a medic, but she can heal if needed. Purple moss is your Esuna.
NO RESINS, those would be en-element abilities that Serah would get if she was a good synergist, and she's not.
Hummanity can be swapped for DB is you're just cheap like that, but the 'cast' time on hummanity is more akin to using potions.
Female character with a pink ponytail is required. Otherwise you look like a hot mess with this equipment.