Okay so somewhat of a shitpost but genuinely the only in-universe explanation I can think of that would have let him die here

Tl;Dr: the second-to-last paragraph is the most important and contains the majority of my idea, the rest is details buildup that is only semi-necessary

So, first off: clearly he had an adation that was supposed go withstand Havoc's energy blasts(1st image), and Darwin very much wanted to live here, or at the very least protect Angel. Second, this isnt the adaption used later. I'm betting it's a difference of external vs internal damage, but still. But it's worth noting that his mutation still is/was capable of withstanding that attack, and I personally think it's unreasonable to assume Sebastian Shaw used more energy to kill Darwin than what he got from Havoc, since why would he waste energy if not necessary?

So, during the iconic moment of his mutant ability trying to figure out what will let him live through this, there's a moment where the energy in his body seems to subside and he seems perfectly fine(2nd and 3rd image), suggesting this form might just he enough to keep him safe. Then, we see this form slowly disappear as Darwin goes back into "normal" form, AND ONLY THEN does the energy start to reappear and shine through the cracks(4th image), then vaporizing him entirely

The final look he had on his face was one of "don't try to save me, I'm already done" which to me is simultaneously an act of altruism, given that he also had his hand extended out to keep Havoc at a safe distance, and him saying "I'm okay with dying, I'm done, you guys got this". Now, do I think this fits the character he was 30 seconds ago? Absolutely not. But it is supported by his previous adaptation being capable of withstanding Havoc's attack, which he seemed completely confident in his mutant ability to protect him and Angel, and to me it seems unreasonable(but this is Fox writing we're talking about) that Darwin could survive and external attack, but not an internal one

There's also a detail I'd like to think is intentional where Darwin adapts before any attacks are actually launched, meaning he can preemptively adapt to something he knows is coming, and that his adaptation is able to be controlled by him. This is also supported by the fact that when the group is testing out his abilities, he's not looking at the chair that gets broken over him, which means his mutant ability can sense danger around him. Using this, I've come to the conclusion that he can overwrite the auto-protection of his mutation, since it seemed to have foreknowledge before(adapting before needing to) but did not predict Sebastian Shaw absorbing Havoc's attack, something Darwin did not know would happen and so he "told" his mutation it would, and as I said earlier, he can overwrite it so that it does what he wants first and foremost

This would mean that he chose to die at the end, and would be the only explanation as to why he did(either that, or he turned into pure energy and has potential to come back in the future, though we should all know that won't happen). Now, as to why he chose to die, I have no idea, it's 20th Century Fox butchering a character for plot reasons because otherwise the movie wouldn't happen

What do y'all think?

So are we 100% Darwin didn't choose to die here?