Riot just released two new blood moon skins on the pbe. http://www.surrenderat20.net/2014/11/1119-pbe-update.html Riot are you just going with the rule of cool now with the blood moon line? is the blood moon skin line no longer canon ? it doesn't seem like elise would fit into either of the roles of the blood moon play.
I was pretty frustrated when I saw too, but I went back and checked my facts. ShadowKnight1224 says it well; apparently "Blood Moon" isn't just for that lore event, but actually just anything that is frightening in Ionian culture. Combined with Ant in Oz' comment earlier, it makes sense that Ionian culture would have scary stories about Thresh and Elise as well.
I mean, I have nothing to do with the lore or Riot, so I can't say for sure, but it still makes sense to me. Both Thresh and Elise are ageless, so they could have been around for long enough to become legends (I mean, the game is called League of Legends, which can be taken to mean the cast of characters is a league of legendary people across runeterra, with or without the retcon). As for Elise, she's pretty deceptive in her means; in her lore, her followers don't seem to fully understand who she is until she's about to sacrifice them. It's precisely that she is a legend is how she is able to deceive them; a person might not believe in vampires or something, they're mythological but sort of dismissed as a fantasy, so her followers might think that of Elise and Vilemaw, so they think they're safer than they actually are.
Don't get me wrong, I'm not questioning anyone's ability into making sense of this, this explanation of yours could as well fit the matter and I thought something along those lines too. What I wanted to point out is that all this is an addition, an edit of their previous take on the subject. Summarizing, it's just the result of a retcon. There was no such reason as those you listed before to justify those skins. To justify them, the retcon is needed and the matter is just as I noted in another topic some time ago, this line of skin was touched by the retcon and so it's not surprising that these skins are now out. This said, the problem I do have with it it's that, like everything with the retcon, Riot's stance is unclear. Without full form stories or wider breath stories about Runeterra we don't basically know what the new lore is and are left with just hypothesis as to whether and why these skins could have a connection to actual lore. The absence of a Riot's official statement on the whole line of skins or of any sort of lore like the JoJ regarding this is but another example of the bad communication pattern regarding lore.
