The Firelord Keyblade can be acquired by buying it for 100 MOS from MOS Market or through the Chest Market from other players. It is also part of the Firelord set + Steel Harpoon for 500 MOS or the Firelord set + 400k coins for 600 MOS. It requires Accuracy to equip and can be enchanted many times using Weapon Enchant Scrolls to get more Aim and Power however this also increases the Accuracy needed to equip it. Be sure you can wield the next level Keyblade before you enchant the one you have. Enchanting is done at the Anvil.