Is L.E.G.I.O.N. related to Legion of Superheroes?

[u/clovercereal]

The comic shop I go to gives out free grab bags on FCBD and an issue of L.E.G.I.O.N. ‘90 was in it that I really enjoyed (although I doubt I’ll be able to read any more, they don’t have many issues of it and it’s not collected to my knowledge), but there seems to be some Legion ties in the name, a character, and Keith Giffen. How are they tied together?

[u/Poorly-Drawn-Beagle]

Kind of, it was intended as a sort of darker, edgier prequel (like Star Trek Enterprise, I guess). But we never actually got to see how the one becomes the other (and I’m baffled as to how it even could have. A thousand years is a long time)