Spoilers below for Better Call Saul's Season 5 finale.
As much as one might hope that science would figure out a way for Better Call Saul to match the same daily output as soap operas, it hasn't happened yet. The AMC drama came to a thrilling conclusion with "Something Unforgivable," which shot a lightning bolt into Nacho and Lalo's now-doomed relationship while also further developing how Saul Goodman's influence is rubbing off on Kim. The space between Saul and Breaking Bad's timelines is getting thinner, and Bob Odenkirk is very aware of the pressure coming.
The big impetus on Season 5 was to properly transition Bob Odenkirk's Jimmy McGill into the familiar Breaking Bad persona of Saul Goodman, which certainly happened. With that all-important journey having been witnessed, Odenkirk think another character now serves as the show's biggest mystery: Rhea Seehorn's Kim Wexler. In reference to Kim's apparent decision in the finale to take Howard Hamlin down, Odenkirk told this to Deadline:
The response he gets is kind of a push-back, and he can’t tell if she’s serious or not. She actually seems kind of serious. I think it all plays along with the fact that we really don’t know Kim. She’s been kind of a question mark that has grown bigger and more mysterious this season than every season. Who is she exactly? What made her? And how is she more than comfortable with occasionally letting her very rigid ethical standards just fall to pieces and blow away? She’s really the mystery of the show now. I think we’re past Jimmy turning into Saul, it’s been a wonderful journey. The question now is who is Kim?
As a Kim Wexler fanatic, every ounce of my being is hoping that she has some kind of confirmable proof of Howard Hamlin's misconduct and malfeasance and all the other troublesome "M" words that apply here. Even if it wouldn't be the most damning sign against Howard's good nature, I could still accept Kim's justification for wanting to make a mountain out of that molehill. However, I'm going to be extremely troubled if she and Jimmy force Howard to fall on a falsely conceived sword, since Howard is the only character on this show with the moral ground to hurt Kim and Jimmy like no one else.
Of course, those notions play into what my expectations of Kim are as a character, and Bob Odenkirk makes it pretty clear that very little about Kim's life is known outside of her current career path and relationship with Jimmy. A flashback earlier this season showcased a young Kim defiantly refusing to get in a vehicle with her somewhat intoxicated (and rude) mother, which informed the depth of Kim's self-confidence and justifiably rebellious nature. But given how much fun she's had conceiving bar shenanigans with Jimmy, how do we know that Kim wasn't as much of a thieving rapscallion as he was?
Is it possible that Kim's downward spiral will get so bad that it essentially cripples their marriage and relationship in Season 6? As fans know, Kim Wexler never got a single mention in Breaking Bad, despite both Lalo and Nacho (Ignacio) getting name-checked on the flagship drama. So it's highly likely that she won't be around for one reason or another. Bob Odenkirk also falls into the camp where Saul and Kim aren't together anymore during the Breaking Bad timeline. Here's how he put it:
I don’t see how they possibly stay together. It could happen, and if anybody can figure it out, these writers can. But, I don’t know, man, I don’t see it. Saul had a carefree energy in him in Breaking Bad; a loner who didn’t have to worry about anyone else. I don’t see how he has that energy and still has Kim in his life, he’s taking chances like working with Walter White.
Also, let's not forget about what happened elsewhere in the Breaking Bad episode where Saul brings up Lalo's name. In a moment that still doesn't completely ring true to Bob Odenkirk, Saul comes out of his office building and says to himself that his assistant Francesca is "killing it with that booty." Considering Saul hasn't shown much interest in women beyond Kim for the past few seasons, one can easily assume the will go through a break-up before he meets Walt and Jesse. Fingers crossed that showrunner Peter Gould finds a way to keep Kim alive through the end of the final season so that she might be like Jesse and get her own solo movie one day.