To Make a Chaos weapon, you will be needing a few things!!
You will need to use the Chaos Goblin to combine Items!!
First you'll be needing a Jewel of Chaos
Second you'll need at least 1 Item at +4+1option
And you'll also need Zen
However the higher the items Lv the more the Success Rate will be ( % )
The best option Lv for Using the Chaos machine to make new items is Lv 4 ( 16 for weapons and Armors, 20 for Shields )
You can Also Use Jewels of Bless to increase the Success rate by 5% for each Bless!!
Ok, when opening the Chaos Goblin Select the Chaos Weapon Combine Button ( Bottom Button )
Then Place all the Required items inside.. You'll see the Success rate at the Top left of the Window!
Click the "Combine Items" Button to complete the combination.
The Chaos Weapon Item is completely random, you will get 1 of the following.
Chaos Axe - This Weapon is for Dark Knight and Magic Gladiator
Chaos Staff - This Weapon is for Dark Wizard and Magic Gladiator
Chaos Bow - This Weapon is for Fairy Elf