it's not really a spoiler, more like my theory, but yeah
Spoiler!
I think Leo's gonna get really badly injured and get into a coma and lose his memory, that's kinda obvious
but
wouldn't it be fun if he lost some of the recent memories and thought that him and JJ we're still together?
and JJ would be too much a of a softie (I feel like he wouldn't be able to correct Leo on that) and he'd just go with it and act like they're together. AND he could use that opportunity to tell Leo stuff that's wrong with their relationship and could fix it as they go (cause they're obviously still in love).
I just feel like that'd be really cool and hopefully not heartbreaking

but
wouldn't it be fun if he lost some of the recent memories and thought that him and JJ we're still together?
and JJ would be too much a of a softie (I feel like he wouldn't be able to correct Leo on that) and he'd just go with it and act like they're together. AND he could use that opportunity to tell Leo stuff that's wrong with their relationship and could fix it as they go (cause they're obviously still in love).
I just feel like that'd be really cool and hopefully not heartbreaking

*wei wuxian's menacing flute noises*