I keep seeing theories on how to fix Karamel, so here's my thoughts.
Both of my theories hinge on the idea that the 31st century must be a mess if the Leigon are coming back in time, so what if in the future all of the heroes were killed, and everything spiraled to the point of deciding to alter history. Presumably the Leigon are the only heroes left in the universe (possibly the near-multiverse even) and given that there are only 6 stasis pods they seem to have potentialy lost many teammates.
My initial impression was that the marriage is a cover, plain and simple. It could be a pre-established cover that they agreed on before they got in the stasis pods, or (my favorite idea) a spur of the moment scrambling for a cover that they agreed on via Imra's powers (because if they had time they could have come up with a less painful cover) And this would make sense as an attempt to not change too much of what for the Legion of SuperHeroes is history, maybe it could mess up the mission if Mon-el gets too close to Kara before they acheive their goal, maybe it could put Kara in more danger and either he is being over protective or that could make the future worse. At some point Kara will find out about the cover and things will go back to normal.
This theory has some possible evidence in canon as Mon-el is still clearly in love with Kara and grips her necklace very possessively as though she shouldn't know he still has it. Also most married couples dont greet eachother with a kiss of that PDA level, typicaly it would be a hug and a peck on the cheek or corner of the mouth, and upon being introduced to Kara, Imra doesn't react as though meeting a romantic rival, but as though she's meeting her hero.
My other theory is both more and less likely, but I think it would add more depth to Imra's character while simultaneously making it so no one involved is the badguy. In this senario the marriage is real, a result of two heartbroken friends finding comfort in eachother after both loosing their true loves. Lightning Lad and Saturn Girl are usualy married in the comics, so what if he is one of the Leigon members who died. As a result Mon-el and Imra, two broken-hearted heroes bacame co-leaders of the team. It could even be possible in this senario that Graym and Garridan were alive and being a good friend Mon-el began helping her with them, bringing them closer, and it may have even been a marriage of convinence (most likely the twins would later have died too). Maybe the fix begins with Imra meeting Ruby (at the DEO or Kara's house or something after her mom is declared missing) and having to leave the room crying and ever concerned about anyone Kara asks Mon-el why such a reaction to meeting a kid, and he tells her that Imra misses her own kids. Maybe Kara decides to purposely change the future so that these children (and people in general) that she's never met will have an opportunity to live, possibly not even realizing that these kids were born before Mon-el was anything more than a friend and teammate to Imra. And how Kara changes the future causes Garth to never have died either, making it so the marriage never existed anymore. Maybe because of something Kara does there are additional stasis pods that appear in the ship, holding Imra's family and several other Leigon members. This would be a very interesting direction to take the story, as it would provide a lot of depth and opportunity for both character and inter-character development.
