If a person is anything but discombobulated, quite the opposite, are they clear headed, enlightened, in control? Or is there a more fitting description?
I think that "clear headed" and "in control" describe the opposite of discombobulated fairly well, if not fully or in a single word. On the other hand, we're talking about a fairly silly word that's used in many different ways. Being out of control doesn't necessarily imply discombobulation, either, so it's really just one facet of what a proper antonym could imply.
I'm not sure "enlightened" works at all. Enlightenment connotes some attained knowledge or state of personal development, whereas discombobulation is entirely a state of mind. An enlightened person, on being abruptly woken from a sound sleep, would be no less enlightened for being temporarily discombobulated.
I would use "composed" or "composure" as an all-purpose antonym for "discombobulated" or "discombobulation" but it lacks a little something in the verb form: I could discombobulate myself or someone else; I could compose myself, but I wouldn't compose someone else. I would instead help them to become composed.