well you sould probably specify a game before anybody can answer this question correctly
You get it when you unlock War.
Causing Chaos
You can free roam in LA Noire at any time, but if you do so during cases, it will affect your rating if you cause chaos and damage. If you want to truly free roam, complete one of the ranks and you will unlock a cost free roam. For example, complete Traffic Desk and you will get to free roam in that rank. Complete Homicide Desk and you will unlock free roam in that rank, etc.
To unlock Feral Chaos in Dissidia 012: Duodecim Final Fantasy, you must first complete the main story mode and then clear the game's requirements for unlocking him. Specifically, you need to defeat Feral Chaos in the "Chaos" storyline and then complete the game's requirements for the "Trial" mode. Once you have done this, Feral Chaos will become available for you to use in battles.
damage
Beat the Chaos Neos Seal in the world of Chaos, first unlock the world of chaos(beat the game) then beat all the players in the neospace area 5 times each, then it will appear and you can try, but you must use chaos neos in your deck so you may not be able to challenge it right away.
The Thing Is you can't Because he's a boss and it probably would not be fair to unlock him but, you can unlock the level where you face him it is in conquest in the Chaos Realm
get the 7 chaos emeralds
STYUPID PERSON WE GET IT STRAIT Away!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
yes there is chaos
To unlock a chaos champion on the game Dungeon Assault, you must have had at least 7,000 renown at any time, and you also need at least one orb of mastery charging to buy one.
To unlock the Phantom of Chaos in God of War III, you need to defeat the game's optional boss, the Phantom of Chaos, located in the Challenge of Olympus. To access this challenge, complete the main story and return to the Challenge area. Once there, successfully complete the trials to face the Phantom. After defeating it, you'll unlock rewards and the ability to face the Phantom in combat.