I guessed because in the preview aangs son said no bender is safe. What could be a threat to a bender, taking away their abilities. But hes the main villain and therefore needs to be a bigger threat than tai lee was in the 1st series, so those are his underlings. And what was the last great thing not really explored in the last series, that abilityNightHawk21 said:I didn't think it would be quite in this way. I thought he'd be trying to build something that would take them away on a mass scale, or he'd turn out to be a bender in the end and wants to eliminate competition for control of the world or something.CODE-D said:Totally called the bad guy having the ability to take away bending. Anybody else? Also hes voiced by steven blum, cool.
My next guess(and I hope im kinda wrong) he takes away korras ability to bend or at least a few before she is saved(or just has one) because after all this is just book one. Then shell have to learn them all over again or search for a way to bend get them back.
Also his story may be bogus and he may not be burned....or hes makos/bo lins father or they were just attacked by the same firebender.