Levi and Eren and what their encounters with Ramzi Tells us about Each of Them:
I'm always endlessly in awe of Levi's kindness and goodness, and I think there's really no better example of the kindness that so defines his character than this entire sequence from episode 87.
Levi is watching Sasha buy ice cream, and watches her overcome by joy and excitement at getting to experience a new food for the first time, to the point she forgets herself and starts talking with her true dialect. He hears what Hange says, about how nobody could see these kids enjoying something so much and think that they're "island devils".
Which is why Levi stops Ramzi from stealing Sasha's purse, because without the spending money Lady Azumabito gave her, she won't get to try any more new foods, and he's seen how much it means to her to be able to.
Sasha says she smells something good and starts off with Connie in its direction, ready to buy more food, and that's when we see Ramzi run into the shot, getting ready to lift her purse.
Levi stops him, but then, when people start threatening this boy, talking about all the things they're going to do to him as punishment for stealing, Levi immediately moves to protect this kid's life.
He grabs Ramzi and picks him up, already seeing how hostile the crowd is turning. The fact Levi picks him up shows he's expecting the crowd to turn violent, so he's putting himself between Ramzi and them.
He tries talking his way out of the situation by telling them Ramzi is Sasha's little brother, but it doesn't work. So Levi just takes Ramzi and runs off with him, telling the others to follow behind.
But then, the truly exemplary moment of Levi's kindness, and his selflessness, comes in the next scene, after they've made their escape.
Ramzi stole Levi's purse while Levi was in the midst of rescuing him, and Levi doesn't even care. He could easily catch and take his purse back from Ramzi, but he just lets the kid go and says, dismissively, that it was "just some change from the Azumabito".
Levi only stopped Ramzi from stealing Sasha's purse because he wanted her to have a good time, but he shows no resentment or anger toward the boy for stealing, either hers or his own money, or any desire to get his purse back for himself. He rescues Ramzi, despite his thievery, because it's the right thing to do, and Levi always does what he believes or feels is the right thing. And he always does what he believes or feels is right because he's a good person guided by his moral principles and values, values and principles that are rooted in his innate empathy, empathy he lets guide him because he's a genuinely kind and compassionate person, even when following those values, when following that empathy, ends in a personal loss for himself (sound familiar? Just like when he let Erwin go).
Notice, also, how Eren is standing in the foreground of the last frame. He's watching all of this unfold. He's watching Levi doing the right thing, and being a good person. It's because this moment of Levi saving Ramzi's life is meant, I think, to contrast directly with the way Eren later "saves" Ramzi from the men beating him up, only to later take the most valuable thing of all from Ramzi, that being his life.
Eren's selfishness is contrasted directly against Levi's selflessness, here. Levi doesn't care that this little kid robbed him, and lets him go scot free, but Eren isn't able to let go of his dream of freedom, and he makes the entire world, Ramzi included, pay for his disappointment with it for not being the way it was in Armin's book.
He "rescues" Ramzi in an attempt to see if doing so will somehow change his vision of the future, but it doesn't. Eren didn't rescue Ramzi because he actually cared about helping him, the way Levi did, he rescued him because he wanted to test the future he saw, to see if that future was something other than a product of his own will. He's mimicking Levi here to see if he can somehow change who he himself is. Someone like Levi, someone who does the right thing. But when the future doesn't change, when Eren sees that, despite his good deed in rescuing Ramzi from those men, he still carries out the Rumbling, still does what he knows will lead to this boys eventual, gruesome death, he's forced to face the truth about himself, which is that he's a horrible person that will stop at nothing to get what he wants. That he's exactly the opposite of Levi, someone who, instead of doing what he believes is the right thing, deliberately does what he knows is wrong.
It's why Eren is crying and telling Ramzi over and over how sorry he is, because he can't hide from that reality anymore. His rescue of Ramzi was just playacting, an attempt to change who he already knew, deep down, he was, and his self-loathing expression is him accepting that, accepting what he really is, and accepting that he can't change how the future plays out because he doesn't want it to.
It's a small, but important moment demonstrating the way Levi and Eren act as foils for one another, and how each of them subverts audience expectations based on their personalities and where they came from.
Levi's the one who came from a life of violence and cruelty, surrounded by apathy and deprivation, and the expectation would be that he, in turn, becomes callous and cruel, while Eren came from a stable home with two, loving parents and an adopted sibling in Mikasa who loves him more than anyone, from an idyllic childhood free of hardship or external violence, and the expectation would be that he, he turn, becomes a good and giving person. But it turns out the opposite way. Levi's the one who's entirely generous and kind, Levi's the one who's deeply compassionate and a genuine hero, doing good for the sake of others only, while Eren allows his anger and disappointment at not getting what he wants to drive him to commit mass genocide, turning him into the greatest criminal and villain in human history.
