Like most people have said, Chaos theory (even though its rng) is more “burst” where burning wounds is a lot more “pad”. Chaos theory, when procced, gives significantly more kill potential than burning wound if you stun someone (especially healers). However, burning wound is also a LOT of damage to the point where it goes beyond pad, because it makes healers have to spend their globals healing over cc/doing damage etc, and that pressure can force people to play defensive.
I played a lot with both last night at ~2800 and my opinion after that is to play burning wound into anything you can reliably cleave (melee cleaves), and chaos theory into anything that will be isolated and with reduced uptime (think wizards or RMP).
TL;DR Burning wound better when you can hit 2+ guys regularly, chaos theory otherwise.
Try necro, it offers a lot more survivability and does big dam, especially with a kyrian moonkin ![]()