You need to find a chaos goblin (Lorencia 142x115 or Noria 179x102), open it and click Regular Combination
You need a key and a chest
And you will receive two open chests that you need to throw on the floor and get one of the following rewards
Golden Box 1 prize out of (Jewel of level, Jewel of skill, Jewel of luck, Jewel of Dark Life, Jewel of Excellent, Jewel of Socket, Jewel of Dark Bless, Jewel of Dark Soul)
Silver Box 1 prize out of (Jewel of level, Jewel of skill, Jewel of luck, Jewel of Dark Life, Jewel of Dark Bless, Jewel of Dark Soul)