If you never saw Babylon 5, that's actually a good way of describing what became of Ironheart, only that in his case it wasn't enlightenment that brought his change about, but the Psi Corps' experiments on him to enhance his already quite strong psychic powers (he was a P10; the strongest Human telepath' ever registered were P12.... I know there is this one person in the books who was a P13, but apart from his most trusted allies noone knew he even was a telepath, so no official record. And Lyta's change never found it's way into any official records either I'd bet).
Needless to say that Babylon 5 was there even before the Star Gate movie was made.
On the other hand Star Trek: Next Generation (Q being the most obvious example, but there were others too) had energy lifeforms even earlier (maybe The Original Series too... if you count that thing that was the manifested hatred of some species wiped out in a war hounding their killers or something like that), but I think Babylon 5 did a much better job with "their" energy lifeforms, as with so many other aspects.
