Elemental Chaos is going to be something you will start getting access to around lvl 500 and shares a striking resemblance to the Belator fights you would participate in to get your skill orbs in the earlier levels of the game. This will be a boss latter climb that will gain you Elemental Cores which are needed to upgrade the Elemental Damage and Defense on your 5th set and going forward.

Potential Loot: Elemental Cores