Beware: serious spoilers below for the entirety of Adventure Time.

Adventure Time is a gift of a show. It’s remarkable for several reasons, not least of all its near-perfect series finale last year.

But maybe its most striking claim to fame is its growth in scope and maturity from a fun kids’ cartoon to an emotionally rich saga. And its most effective — and most enduring — leap in this direction is its empathetic treatment of Ice King, the erstwhile goofy villain.

Ice King begins Adventure Time‘s run as the bad guy, a crazy old wizard obsessed with kidnapping and marrying princesses, whom our heroes Finn and Jake perpetually beat into submission. He’s a little bit evil, but mostly he’s ineffectual, silly, and sad.

In Season 3, however, his tragic backstory begins to unfold. It’s revealed that he was once Simon Petrikov, a kind and brilliant academic who stumbled across a magical crown a thousand years ago. The crown kept him alive through the nuclear holocaust that wiped out most of humanity (bad news for us, since it becomes apparent that this devastated past is our present), and it gave him the power to protect Marceline, the orphaned child he adopted in the wasteland of the world. Every time he wore the crown, however, his grip on his sanity loosened a little more, until he completely lost his sense of self and became Ice King.

This information is doled out in remarkably few episodes, and they are arguably the show’s finest. Marking some of the earliest forays into more serious themes, they succinctly and elegantly tell a story of loss and sacrifice that delivers more character development than you can shake a stick at.

It’s also helped, in no small part, by the incomparable voice work of Tom Kenny (yes, SpongeBob) who plays both Simon and Ice King with beautifully subtle differences that are all the more striking when you witness his transformation from one to the other.

In the present, adult Marceline has trouble coping with Ice King’s madness and memory loss. Their relationship has all the notes of living with a loved one who has dementia, except both Ice King and Marceline are immortal, and she’s been living with it for a thousand years. It’s enough to make anyone balk.

After the stellar Season 4 episode “I Remember You,” however, Marceline warms toward Ice King. She begins to appreciate the person he is for the sake of the person he was, and as she shares his story with her friends, they do too. Finn and Jake treat him much more kindly, calling him Simon, inviting him to parties, and even letting him move in with them. This change has a profound effect on Ice King — he stops kidnapping women, his desperate loneliness wanes, and he all but loses his position as the show’s villain.

He’s still goofy and sad, but he’s a real person. And a sympathetic one at that.

It’s a change that’s born out of pity — Ice King’s friends treat him well for Simon’s sake — but it has the unexpected effect of encouraging him to be less pitiable.

Because, importantly, Ice King never remembers his past identity. A handful of times we see Simon’s consciousness trapped inside, but Ice King is unaware of him to the end. They are, for all intents and purposes, two separate people. So when Ice King responds positively to kindness and friendship, it’s completely his own doing.

This creates a bit of an odd loop. Ice King’s friends treat him better because of the person he used to be, but in doing so they help improve the person he is. Through their pity for someone they see as a product of madness, they reveal that madness’s humanity.

But that’s a hard pill for people to swallow. Whenever Ice King shows signs of reform or growth, they tend to see it as Simon shining through. This only increases the intensity of the loop, as treating Ice King more like the person he was as Simon allows him to slip more easily into the role. It’s a clear lesson in empathy that’s signaled strongly by the show, even if the characters often miss it.

No one is more guilty of missing it than Betty, Simon’s fiancee, whose obsession with curing him consumes her life.

When Betty first enters the show in Season 5, her presence is a glimmer of hope, a wildcard tucked away in the background, ready to change things radically just as soon as she’s called upon. She vows to reverse the crown’s effects, and she seems capable enough to do it. And Simon, in a fleeting moment of clarity, agrees to keep living as Ice King for as long as it takes her to figure out how to save him.

But somewhere along the way, Betty’s efforts sour. She sacrifices her past, her present, and even her own sanity all in the name of restoring his memory, and none of it works. Meanwhile, Ice King flourishes on his own, becoming a vital (if still goofy and sad) part of Ooo, and one of the show’s most beloved characters.

These conflicting arcs come to a head in the Season 9 “Elements” miniseries. Ostensibly a straightforward struggle to save Ooo from a bad case of magic-gone-wrong, at its core “Elements” is about Ice King’s personal growth clashing against Betty’s insistence on restoring him to what he was.

After years of failed attempts, Betty decides to try “the direct approach,” asking Ice King out on a date. Immediately responding positively to the attention, he gets himself a bespoke suit, he stops visibly wearing his crown, and he even gets a pair of little round glasses he wears low on his nose.

He looks, for all the world, like he did when he was Simon.

And his coherence increases tremendously. He rescues the kidnapped Betty (a telling reversal of his original M.O.), he’s committed to restoring order to Ooo, and he’s genuinely helpful and pulled together — if a little loose around the edges. He looks and acts the part; it’s so tempting to believe that his memories are resurfacing and that Simon is coming back.

Betty’s certainly tempted to believe it, and who could blame her?

But it’s not true, and Betty’s attempt to accept him crumbles into disappointment and desperation as she realizes that even this sane-ish man in a suit is not the fiance she used to know. That desperation leads her to betray Finn and use the magic gems he’s collected not to set the present to rights, but to alter the past. She can’t come to terms with the person Simon has become, so she makes a last ditch effort to make it so he never changed.

“People say you shouldn’t live in the past. But I say: Why not!” Betty preaches. She has big plans to open a portal to the past and drop Ice King’s crown in a volcano, making it so he never existed. She really gets on a roll with her plan to make everything better, speculating that she might even avert the Great Mushroom War, the nuclear holocaust of a thousand years ago.

Our favorite inter-dimensional losers Prismo and the Cosmic Owl are horrified by this last point, and we should be, too. We don’t need to worry as much about paradoxes and timelines, but the implications of a world without that cataclysm are dreary. (We even saw it at the beginning of Season 5). The war may have been a real bummer for everyone involved at the time, but something beautiful eventually came out of it. It’s how we got Finn and Jake. It’s how we got magic. It’s how we got Adventure Time. Things got better and the world healed itself, not by going back to what it once was, but by becoming something different.

Changing history so drastically would do away not just with Ice King, but with everyone we know and love.

And so Betty’s insistence on altering the past, rather than saving the present, is inherently backward. It comes from a place of love, and it’s hard to fault her for it, but within the show, it simply can’t stand.

The person who realizes this and saves the day is, fittingly enough, Ice King. Possessed with newfound self-worth (born out of everyone’s new efforts to take him seriously) he stands up for himself and delivers the most moving line in his long history:

“Lady, this Simon sounds cool, but I’m Ice King. I guess I’m a special person, and I am worthy of respect.”

He short circuits Betty’s magic and saves himself and Ooo, blowing up his bespoke suit in the process. His go-to blue muumuu bursts back out into existence, revealing the bizarre fact that he had it on underneath the whole time. It’s a fun gag, but it’s also proof that Ice King was himself all along. Simon’s memories were never informing his actions; he was just responding, as people often do, to being treated well. He was shown respect, and he found respect for himself, and that respect is what saved the day.

When he returns to his “Classic Ice King” look as he calls it, he’s no less the person he was. If anything, he’s much more.

Meanwhile, Betty’s obsession with curing Simon becomes even more destructive. In the series finale she summons Golb, an all-powerful being of chaos, and very nearly ends life in Ooo, thus completing her transformation from signal of hope to ultimate villain, the final boss in a decade-long string of dungeon fights.

As always, Betty’s intentions are good, but the show insists that no good can come of them. Restoring Simon, while a noble cause, is tantamount to killing Ice King, a character we started to love for Simon’s sake but have since come to love for his own. It’s a theme of saving-turned-murder that’s extrapolated several times into the destruction of the world as we know it.

This brings us to the interesting question of what it means to “heal” someone at all.

Eye color is a telling feature in Adventure Time. Most characters — humans, in particular — have black dots for eyes. It’s a pleasantly simple design that carries a lot of weight when it varies, such as with characters who’ve had their minds altered by magic, whose eyes are always white.

Magic Man has these eyes. So does Peppermint Butler (always a devout student of the Dark Arts). So does Ice King, and so does Betty, after she acquires Magic Man’s power and starts to lose her grip on reality.

And, critically, so does Simon. The very first time we see Simon in “Holly Jolly Secrets Part 2,” his eyes are white, while in an old photo of him and Betty, they’re black, suggesting that the crown has already started to transform him.

But every other time we see Simon — when the crown’s powers are negated, when he’s in his own head, even when we flash back to his life with Betty before he found the crown, his eyes are still white. Simon was a scholar of arcane magic, after all, and this flashback, in particular, suggests his mind was already being altered without any help from the crown.

But that’s not necessarily a bad thing.

In the series finale, Ice King, Betty, and Finn are swallowed by Golb and slowly digested down to their “most essential forms.” Betty loses her magic and madness, and Ice King reverts to original Simon — pocket square, bowtie, elbow patches… and white eyes. It’s hard to qualify just what it means to be your most essential self, but for Simon, that apparently means being just a little bit unhinged.

And it makes sense. Magic or no magic, this pure form of Simon has still lost the woman he loved, wandered through a post-apocalyptic wasteland, sacrificed himself in increments to save his adoptive daughter, and spent a thousand years trapped in a labyrinth in his head.

Betty may have lost her mind over a short time by force of will, but Simon has had some serious life experience.

In a similar vein, Finn’s missing arm isn’t restored by this digestion process, either. One of Adventure Time‘s more fascinating threads of continuity is the fact that no matter the timeline or incarnation, the essence that is Finn always loses his right arm. And that’s okay. Just like Simon, he isn’t “made whole” in an easy sense, and the things that have made him who he is aren’t expunged.

The show has a clear lesson to teach: your most essential self might not necessarily be your simplest or your earliest iteration. Trauma can be edifying, and change can be a vital part of becoming who you are.

But if Simon’s essential form is already altered by magic and by ordeal, then who exactly has Betty been trying to save? It’s an added layer of futility to her struggle, a reminder that achieving her goal wouldn’t only kill Ice King, it would alter the person Simon has become, too.

Both of them may have changed, but neither of them is in need of changing back.

The fact remains, however, that Simon and Ice King can’t exist at the same time. They are two unique consciousnesses in one body, and prioritizing one would doom the other. Whether by accident or by design, Adventure Time‘s greatest lesson in empathy backed it somewhat into a corner. One of the audience’s oldest and most fervent wishes is to see Simon restored, but to do so would essentially kill Ice King, a character the audience knows and loves much better.

What can you do?

You do precisely what Adventure Time does in its series finale. Unable to abandon Simon or destroy Ice King in good conscience, it splits them. Simon is digested by Golb just long enough for his body and mind to be restored, and then he’s rescued. And so the world is without an Ice King for all of 30 seconds, until the crown, in search of a new master, finds Gunter the penguin.

And Gunter’s deepest, truest wish is, it turns out… to be Ice King.

It’s a lovely echo of the original Gunther, a little dinosaur whose wish millions of years ago to be like his teacher started this whole crown business.

And more importantly, it’s a chance for Ice King to live on. He may look a little different, but he’s got the same voice, muumuu, and penchant for drumming. And since the first words out of his mouth are “Say, where’s Gunter?” it’s clear that his penguin memories and identity are gone.

As far as we need to be concerned, he is Ice King.

If the show’s addition of Ice King’s backstory was its first sign of maturity and depth, this conclusion is a sign of something much greater. Rather than adhering to the knee-jerk solution (and possibly the original goal) of healing Ice King and reverting him to the person he once was, it respects the worth and the autonomy of both characters, and it gives them both a chance at a happy ending.

And they both get it, to an extent. Whether the new Ice King is a little better with the ladies, or it’s just a logical step in his improving self-respect, he finally marries a princess. Simon has a tougher break (Betty sacrifices herself to save him and Ooo) but his memory and sanity — whatever that means — are restored for good.

Glimpses further into the future suggest trouble — Ice King eventually turns into a monster and a new kind of antagonist, and Simon launches his own impossible crusade to save Betty — but that’s in keeping with the spirit of the finale. There are no true endings, happy or otherwise. Things change, people evolve, and no one time is more real than another.

And while the future of Ooo is dark and uncertain, the end of the finale shows a more peaceful and quotidian present — Ice King and Simon living side by side, having a nice night in with their family.

It’s about the happiest ending we could wish for, and the only reasonable solution to a mounting problem that the show built for itself as it matured by leaps and bounds over the years.

Adventure Time did a lot of things superbly over its 10-season run, but its compassionate and evolving treatment of Ice King might be its best. It’s one thing to give your mad villain a tragic past… it’s another to use that tragedy to cultivate his madness into its own viable character. Its commitment to Ice King’s growth is beautiful, and its answer to his and Simon’s autonomy is perhaps the greatest example, among many great examples, of just how much the show grew up, and how much it had to teach us.