might i suggest an even more complicated and emotional au...widower!Jean
don't make me cry??? :"((
goodness, jean would have such a harder time if his wife, i'm assuming mikasa here, DIED???
the way he would put her on a pedestal, nobody can ever measure up, literally the only thing that would keep him going would be their child..................................... this man would have dead wife syndrome.
gosh this would make things so complicated with reader too, if she still has the same divorce story line, i can see her feeling so inadequate. at least in second chances, she has some solace that jean fucked up too. but in a widower!jean au, good lord, i can't imagine being in her shoes, feeling like a failure and then feeling like she could never measure up to Dead Wife. but on the other hand, reader might not feel as much jealousy or competition. so in that sense, the complication eases.
this would be soooo interesting to explore - maybe as a bonus chapter after second chances is done?