The 1084 that you got from Aldo quenches fine in oil. I use peanut oil. The charcoal fire may be part of the problem. It's been use far, far longer than gas but you really have to pay attention that the heat in it is even in the fire. Some people bury a black iron pipe in the burning charcoal big enough to heat their blades up in it. This will involve having a long forge unless you only heat treat short blades. You might try moving you blade back and forth in the charcoal to help reduce or eliminate uneven heating. There have been several posts on straightening blades. You could look them up. We all do what we can to prevent warping but sooner or later, usually sooner, we all have to straighten blades. One other thing that you didn't mention. Did you normalize the blade before hardening? If not it's a good idea. Three cycles, done correctly, not only refines the grain but helps remove stresses built up in the steel during forging and machining.
Doug
P.S. I just checked and the post that was following this one at the time I posted, the one about heat treating 1080/15n20 damascus, contains some methods to try to straighten blades.