I only troll trolls, dude. You said a Rioter said it but you won't go through this massive thread for us and pick out the evidence, and instead just keep insisting its there. We believe things confirmed by Rioters, sure, if someone provides the evidence.
On top of that, magic is magic, there's nothing in the lore to suggest that magic is specifically associated with any culture other than specific types of magic being associated with a culture: Elemental magic being associated with Ixtal is a big example, but that's not to say others like Annie don't use elemental magic as well. Annie has nothing to do with Ixtal despite using elemental magic like they do.
And third, Garen's sword's magic is only "associated with Targon" because Kayle is associated with Targon. Garen isn't using "Targonian" magic, Kayle is. If anything, this is only supporting that Kayle is associated with both Demacia and Targon and NOT that Garen is associated with both. If you have to go through another character to say he was associated with Targon, he's probably not very closely associated with Targon, is he? He's associated with Targon in the same way all Demacians are associated with Targon because Kayle and Morgana were big influences in Demacia's early days.
Can't wait to hear what confusing and/or obliviously insistent response you have.