This article contains major spoilers for “Invincible.”

If you’ve read the “Invincible” comics and know the endgame, then you’ve probably been watching season 3 with dread. Not because the season is bad, far from it. No, because you knew the ending was going to be a bloodbath and that one major character wouldn’t be making it out.

The penultimate episode of season 3 — “What Have I Done?” — adapts “Invincible War.” Angstrom Levy (Sterling K. Brown) enacts his latest revenge scheme against Invincible/Mark Grayson (Steven Yeun) by bringing Invincibles from different realities to his. To go home, the Invincibles have to destroy Mark’s Earth, “our” Earth.

One of the Invincibles, and an especially sadistic one, attacks the Teen Team base, overpowering Robot, Monster Girl, and Bulletproof. So, Rex Splode (Jason Mantzoukas) stays behind to fight him and let the others escape. When it seems like all is over for Rex, he plunges his hand through an open wound, grabs his own skeleton, and detonates it, taking out himself and the alternate Invincible in the explosion.

Rex has been compared to Gambit from “X-Men,” since they’re both cocky ladies’ men with the ability to make things go boom. (Granted, Rex can generate glowing/exploding rods, while Gambit sticks to playing cards.) Comparisons will now doubtlessly be made to Gambit’s heartbreaking sacrifice in “X-Men ’97.” Like Remy LeBeau, Rex Splode is a hero who deserves to be remembered.

In both the “Invincible” comics and TV show, Rex isn’t meant to be likable — at first. He’s cocky, abrasive, and dating Atom Eve (Gillian Jacobs, one of the show’s many celebrity voices). Rex’s very presence is standing in the way of Mark and Eve getting together. Then, worse, Rex cheats on Eve and she dumps him. That could’ve been the end for Rex, but instead he hung around. Spending more time with Rex let you understand why Eve liked him in the first place.

The show has redeemed Rex even more so than the comic. Part of that goes back to Mantzoukas’s funny and entertaining performance. He walks a fine line between making Rex obnoxious, sometimes pathetic, and ultimately endearing. The show has also given Rex more time in the spotlight, which means his absence will feel even more obvious and painful in future “Invincible” seasons.

Rex got humbled back in season 2, when he led some of the Guardians of the Globe on a mission gone horribly wrong. He and his teammates almost died, which gave Rex the wake-up call he needed. He was still a loudmouth, but one that cared about his friends.

Season 3 has paired Rex up with Shrinking Rae (Grey DeLisle), who is having doubts about the whole superhero thing. A normal life sounds good to Rae, but as much as he likes her, Rex’s whole identity is being a superhero; his nom de guerre is his literal, legal name, after all. Watching Rex and Rae’s scenes together, part of me hoped the show might stay its hand and let Rex live this time. Alas, it wasn’t meant to be. 

Rex Splode couldn’t give up being a hero, so of course he died as one. 

“Invincible” is streaming on Prime Video. The season finale premieres on March 13, 2025.