Follow up to a previous question but: how do you think morena and meruem would react? Something I note is that meruem/chimera ant arc never expoicitly disagrees-from the rose bomb montage we are absolutely shown how humans can be depraved and sickened. But it is aknowledging that the two are both sides of the same coin (hyori ittai and all) that good and evil coexist and that humanity has the capacity of good just as much as it does evil-hence why meruem gives up his conquest by choosing to focus on what little good does exist in the world. I think meruem for his part would pity her because he aknowledges that morena is a victim of that cruelty (considering she is human and has experienced it first hand while meruem was only alive for a little over a month) while at the same time resigning himself to aknowedging that he could not change her determination but I am not sure how morena would react to him.
Ahhhh this is so interesting to think about!!! I like your assessment of Meruem's potential reaction; in his final moments, he seemed like someone who was a little more at peace with the world and his place in it, and I don't imagine he would start gearing up for a fight. Meruem is such an interesting character in that we see how drastically he is able to change over the course of his (tragically short) life; I'd be curious to see who Meruem would have become if he'd lived longer. I imagine he'd continue to grow his knowledge of the world and the people in it, which would no doubt affect his personal philosophy--so the question then becomes: if he meets Morena, will that change anything in him? Not that she would turn him evil LOL (that would be antithetical to his character arc), I'd just be curious to see how meeting a person with such an extreme worldview would impact his own. I imagine his curiosity and desire to learn would probably manifest in him trying to have a lot of conversations with her, and doing a lot of thinking and philosophizing afterwards.
On Morena's part, I'd also be really interested to see how she reacts to non-humans! Her vendetta, as I interpret it, is specifically against humanity and all its evils--so, does she lump in Chimera Ants with humanoids and dismiss them as just more numbers on a kill list? Does she view them as superior beings? I'd argue no to both: the way I see it, Chimera Ants as a species just make sense to her.
Humans kill each other without reason or purpose, inflict an incomprehensible amount of suffering on those we arbitrarily deem as enemies or nobodies. The Ants also commit some heinous acts by our standards (killing children, eating people, planning a genocide) but it all stems from a commitment to natural law: survival of the fittest, propagation of the species above all else. The Ants act as a cohesive body, whereas humans are a mess of disorganized individuals. And their kills usually (with some obvious exceptions) stem from their need to eat. It's all very law-of-the-jungle. And the closer the Ants get to being human, the more they turn away from that cohesive system and become individuals. You might argue that's a good thing (as it often is!) but it comes with the tradeoff of Ants acting in their own self-interest, i.e. killing for fun rather than survival. Meruem himself recognizes this, and brings it up to Netero before their fight:
And here's where Morena's philosophy steps in: similar to Meruem, her largest issue with humanity is not just the nature and scale of our evils, but the randomness of it.
Morena doesn't just see humans as evil, she sees humans as pointless, existing cause nothing but suffering and misery. On the other hand, even when he looked down on humanity, Meruem simply saw humans as lesser beings--he didn't hate them, any more than we hate cattle (he basically makes this same analogy to the attendants in the palace). We're just a food source to them. Morena hates humanity, and there lies the crucial difference. She's pretty unwavering on that front. I believe she's probably see early Chimera Ants as animals, just doing their job and propagating their species. The further away the Ants got from their roots (and thus, the closer to humanity), the more Morena would be forced to apply her same logic to them. If they get too human, they've got to go.
But as we can see, she's perfectly capable (and often interested!) in holding conversations with fellow humans. So, going alllll the way back to your original question: If Meruem and Morena were to meet, what would happen? I think they'd talk. And talk and talk and talk. And then Morena would probably introduce Meruem to card games and they'd be locked in an epic gamer battle henceforth ;)