First of all, I must say that it's more of an endgame thing, but there's too much RNG involved if you want some optimal weapons (which you do not depend to clear the main story - might have a hard time doing it with AI instead of other people though):
- create the weapon you want. You want it to be at least of Rarity 6 (it goes from 1 to 8 and is random);
- check the growth rate for it. It's random. You'd want it to be 1;
- check if it's an late bloomer (late bloomer weapons have bigger % to stat increase at higher levels, resulting in better stats than an early bloomer later on). Random;
- the attributes if comes with are random too, but they can be removed if needed.
So, a bunch of RNG things after, you have your pretty weapon. Now it's time to get some nice attributes (buffs) on it. You can "feed" a weapon with another one. The attributes from the fodder will carry on, but:
- it's not guaranteed that all the attributes from the fodder will carry over;
- it's not guaranteed that the attributes from the original weapon will be maintained;
- the resulting weapon can get some new attributes, some of which are bad.
Now, you can have some kind of control here - there's a fixed amount of maintained, inherited and new attributes depending on the rarity of the weapon, so you can have a fodder only with good ones to be inherited. There's also some items you can use during fusion to shield the attributes of the original weapon from being replaced/removed. Finally, you are able to remove bad attributes for a price in EP.
"Well, but I can save scum if I get a bad roll, right?"
Kinda. Freedom Wars has no save slots, saves immedialy when you begin crafting something, and saves again right after the crafting is done (it takes some minutes, but can be sped up with specialists), so you can't just close the game and load it back - you need to upload you save to PS+ (or PC/PS3) before you start crafting, and if you don't like the results you quit the game, roll back your save, and do it again.
So it's just overly complicated. In other "hunting games" you just need to farm materials and craft shit, but here there's just so many little details to go to get a good endgame weapon (not even talking about god tier stuff) that it breaks the flow and tires you out.
But even than, I love this game so much. If you guys need help doing missions and we can manage to even timezones differences, I'm in.