All in one package, just drop it in your custom folder.
Quest giver can be spawned using [add jack
quest will ask the player to gather 15 fire crystals. they are scripted as loot on the flame elementals. (custom droprate) when completed you will get "the flame" . to be able to use the flame on also has to find the Firestone. (dropped by flame beetle also adjusted droprate).
The firestone is needed to light up your bolts. this way you can shoot flaming arrows.
Could be you have to edit the damage of the crossbow a bit, haven't tested it on a live server. just shot some monsters with it on an empty server.
Please give me some credit as this is the first script I made.