This PDF continues the great trend of other Lost Classes. The Chaos Witch is an interesting class, one that should be able to find a home in pretty much any campaign, whether as a PC, NPC or foe. The concept is interesting (anyone who reads Marvel comics should have no problem identifying the inspiration) but not disruptive, adding a good element of surprise (and how!) to the game.
The mechanics are well thought-out and balanced overall. The entry requirements are easy to achieve, including a roleplaying entry allowing the GM to customize the class to his/her world. As a magic-based class, however, I don't understand the need for a BAB requirement.
The class abilities are excellent, truly embodying the concept of a Chaos Witch; you never know what you're gonna get, but chances are it won't be pretty. The Change Outcome class ability, a written, could be a little too powerful at the higher levels, but in the end that depends on each GM's level of play.
For the price, it is an excellent addition to any GM's arsenal of tricks.