The Season 5 finale of Pretty Little Liars gave us the biggest clue to A's identity yet, but in true Pretty Little Liars fashion, it still left plenty of questions unanswered. Charles DiLaurentis is A, but while we know this man's name, we don't yet know how he fits into the puzzle overall. That's not to say that the world doesn't have their theories: The biggest one is that Charles is Jason DiLaurentis' twin brother, which almost seemed like a fact after we witnessed the home video of two blonde boys with Mrs. DiLaurentis and a baby Ali. I've been sold on the Jason's twin theory for a long time now, but knowing Pretty Little Liars, not everything is as concrete as it seems.
While I'm definitely leaning towards the Charles-as-Jason's-twin theory, even I know that we need to start opening up our brains to see more than just that narrow idea. After all, Pretty Little Liars convinced me that Mona was dead and gone, only to bring her back in the finale alive and blonde. There are a million different ways that the Charles storyline could go, so we shouldn't be 100% positive that the situation is exactly as it seems. If Charles isn't Jason's twin, then who could he be? Here are some ideas:
THEORY #1: Charles Is A Sibling And Not Jason's Twin.
It seems likely that Jason and Charles are twins, if only because he would have attended prom in the same year as Jason, Melissa, and Ian if he was the same age. But what if instead he was just a little bit younger than Jason? It might explain why he seems particularly fascinated with Ali — maybe he felt that she stole his place as the youngest child.
THEORY #2: Charles Is An Obsessed Former Friend.
Maybe Jason and Charles were best friends growing up, so much so that they became like pseudo-siblings. Charles could have desperately wanted to be a part of the DiLaurentis family that he wedged his way into their family, only to be rejected later in life.
THEORY #3: Charles Is Jason's Alter Ego.
Maybe there really was a twin named Charles, but Charles died years ago. What if Jason took on Charles' personality after his death, and now doesn't even realize that he's working as A/Charles? It'd be a huge stretch, but hey, so was theorizing that Jason had a twin.
THEORY #4: Charles Is Mr. Hasting's Son.
Mr. Hastings talks about taking "the kids" to the Campbell Apple Farm in the fall, which is where Charles has his lair. What if the kids included Charles, the secret son of both Mrs. DiLaurentis and Mr. Hastings? They could have given birth to not one but two children together during their extramarital affair, and both could have been responsible for sending Charles away.
Sure, all of these theories are plausible, but my money is still on Charles as Jason's twin. I'm calling it like I see it on this one.