Inferno weapons are the newest addition to Ignite Flyff, These weapons will drop from the new Cairos Raid dungeon.
They will no longer use the method of upgrading with Sunstones or Shining Oricalkum, instead they will use Inferno Upgrade Scrolls and Inferno Piercing Scrolls.
These scrolls can be found in the NPC next to the Cairos Dungeon entrance in Flaris.
Once you obtain these scrolls, it's as simple as double clicking them to activate and using them on your Inferno Weapon ( just like using sunstones).
The upgrade chances of both scrolls are 100%, so the time it takes to upgrade your gear will come from obtaining the Raid Chips themselves.
The weapons gain Diamond sockets at +6 and onward, the same as Ultimate weapons. You can use diamonds on Inferno weapons with the same method as Ultimate!