Living Flame, Crius, Atlantean Avenger, and Hydra Hunter all come from materials dropped from the bosses at the end of the 2nd round of levels after the initial 5 elemental levels (earth, water, fire, spirit, air)

fusing can give you the regular version and you can level it to 15 to unlock the + version but you'll still have to gather materials to craft the +version

also most quests have overlapping requirements, and you'll probably end up gathering more materials than are needed for one crafted armor (usually the regular non+ version as your first one)

I think I was lucky in receiving regular versions from daily log in prizes, event prizes and chests rewards from keys I got from leveling up, so when I used my materials, I only had to make the +version