How do you fight a boss on GunZ the Duel

Aquire "boss items" by either running regular quest mode, most the time with at least torn page thirteen, which the enemies drop, or to fight the tougher bosses beat the smaller low level bosses like the fake goblin king (items: Goblin skull, Goblin doll) and they will drop boss items for the higher level bosses.

To fight a boss on Gunz you need to get quest items/sacrifice items. There are also item combinations for certain bosses, such as the lich, where you need the Devil's Dictionary and an enormous bone (or something like that). Usually you get sacrifice items from quest level 2 through to 5 but you need torn page 13 and you need to be level 13 or over (you need to buy torn page 13 with bounty from the shop).