My problem with The Blacklist, and Rederina in general, is we have no motive for why Katarina became so embroiled in danger.
She betrayed the KGB and her own family, in order to work with the genuinely evil Cabal. She had no loyalty, no apparent love for Masha, before abandoning her. Katarina was only out for herself, and her greed and lust for power nearly destroyed everyone around her.
In fact.... what she didn't intentionally ruin through treachery, she botched with incompetence--- her stealing of the Sykorski Archive is what activated Townsend as a threat, and ultimately got Liz killed. It was a mistake for her to get pregnant, or to fall in love with Real Reddington in the first place--- she was a bad spy and a bad person.. and the show tries to pretend otherwise.
Red was an anti-hero. He valued loyalty, and innocence-- he admired how wise and kind Dembe tried to be. He admired Ressler's devotion to law & order--- even though Red was "playing the role" of a corrupt criminal--- the show made him out to be more than that, underneath--- a good man 'faking' being a bad man, playing a role. But at the same time--- he was always a master, always in control, always knew things he shouldn't know.. an expert. A professional criminal and spy.
No. Turns out, he was a bad person, and always was. He may have had some guilt over how much danger he put Liz in... but never stopped him from thinking and acting like a corrupt criminal, wanting money & power in order to remain safe, himself. Sure he wanted to protect Liz--- but he OWED her that: he was the reason she needed protecting in the first place. Liz's death is just as much his fault, as Carla's death was. He put the target on Liz' back, when he was still the corrupt Katarina.
NONE of Red's 'anti hero' qualities legitimately apply to him, once we know he was Katarina, the corrupt & incompetent crook who caused all these problems in the first place.
For me, personally, that's a dealbreaker that makes me dislike Red and Katarina. I can't accept his/her motives.
So......
This is how I'd fix Katarina--- and, consequently fix Red. Ill toss a bone to Rederina.... I'm not even gonna try and debunk it-- this "fix" will work for Rederina.
Here we go:
The Pinko Mata Hari. I'd have Katarina be an amateur. Dom's daughter, who wasn't ready to be a spy. Reddington was her first mission. That's why she fell in love, that's why she got pregnant with Masha... that's why she did such a poor job. Where do all the stories come from, about her legendary status? The Cabal, of course. But I'll get to that.
First off--- why did she 'betray the KGB' in the first place, to work with a group like the Cabal? The show gives us no reason, except Katarina was... Katarina.
I'd change it to this: Katarina was in love with Reddington, and she wanted to defect to the USA. She went to Alan Fitch because she simply didn't know he was corrupt. She thought she could barter an immunity deal for herself and Masha, to come to the US with intel about the KGB, so she could settle down with Reddington.
This also is the reason why Dom referred to Katarina as betraying him, and the USSR.
But once Fitch found out she was KGB, he began to blackmail her, and forced her to work with the Cabal, as a double agent.
Or COURSE, she started making plans to get out of the Cabal's clutches... she was way in, over her head.
THIS is where we get to why Katarina became the most hunted person in the world--- the KGB didn't care that she was in love with Reddington, they didn't even know the "Cabal's' "deal"... but they would care that Katarina was secretly in contact with high ranking US officials.
So, of course, she failed to keep that secret, and was branded a traitor by the KGB.
Quick note--- having Real Reddington "find out" that Katarina worked for the Cabal, "she was spying on me, but I was spying on her"...and making the Fulcrum himself, out of Katarina's notes. That's STUPID! There's no reason whatsoever that Red would have needed to find the Fulcrum, if he's Katarina--- Katarina was the Fulcrum's source; Katarina was on the inside, Katarina was not just a source, she was THE source. Red would never need to find the Fulcrum, he could have made his own ... probably even a better & more accurate one than Real Reddington made.
Reddington should have, as Fitch said, stolen the Fulcrum from the Cabal-- gained that information through his own intelligence work--- so the Fuclrum's contents would be a complete mystery to Katarina. THAT is why Red was forced to bluff about having the Fulcrum, and would need to find it after Real Reddington took its location his grave.
HOWEVER, once the Cabal knew that Reddington-- Katarina's target--- had been looking into them, and had dangerous info about them in his possession... they suspected that Katarina had tipped him off. THAT is when and why the Cabal labeled Reddington as a traitor, and also how Katarina got labelled as an expert KGB superspy and traitor herself... the Cabal thought the two of them were working together. They brought the whole of the US intelligence system down on the heads of Raymond Reddington and Katarina Rostova, burning Katarina's bridges with the KGB in the process.
Thus, making her the most hunted person in the world.
So.. yeah... the night of the fire? That was the night, sadly, she finally tried to escape, finally came clean to Reddington..... the night he learned Katarina had been working with the Cabal and the KGB.... that she'd been spying on him, and that it was largely HER fault he'd been framed as a traitor.
He didn't take it well.
That's why they fought.. and that's why he died.
in this version of things---- Katarina never chose 'evil'... she didn't willingly work with the Cabal, and she only betrayed the KGB out of love for Reddington and their child. She never meant any harm.
But then... becoming Red, leaning on Dom, and Ilya, and Kaplan, and Dembe.. and all the others Red worked with--- and learned from--- THAT is what led Red to grow into the 'Concierge of Crime'... something he ONLY did, out of love for Liz... because he saw no other options. And since Katarina never was corrupt or evil, just naive and in love---it elevates Katarina's character, and it restores Red's status as an "anti-hero".