That’s nice, and as much as the “you don’t know what plasma is and I am an expert” banter is interesting… I already know plasma is ionized gas. Whilst science was certaintly not my greatest subject in academics, I do know the fundamentals of it. The reason I mentioned plasmabending as being an attribute of firebending is solely based that the average writer (they’ve given lavabending to firebenders before giving it to earthbenders and done major disservices to their own lore on other occasions) would connect that lightning due to the fact superheated plasma and other scientific mumbo-jumbo forms storm expulsions such as lightning bolts which in the Avatar universe is fire because “reasons”. 

Lightning = Discharged Plasma
Lightning = derived of Firebending for reasons
Forms of Plasma = Firebending somehow

It’s not what I would do if I was a writer of Avatar or running an AU, but I think it’s what the creators would do for their canon given circumstances and such.

This all isn’t important anyway, so we should stop before one of us become antagonistic and instigates an argument and thus garners moderator attention.