So I’ve rewatched this episode a few times at this point, and each time I noticed new things about this scene. As more pieces fell together, we get a clear picture as to just how brutal Lars’ death was.
And this specific screenshot says it all.
Why? Because LARS IS CLEARLY STILL ALIVE AT THIS MOMENT. (Look at how tense his facial features are. There is no way that Lars could make this face if he was dead right now.)
Why is that important? Look at what happened seconds before, and what happens shortly after.
1) The explosion.
The robanoid had just exploded, and Lars was physically on top of it when it happened. At this point-blank range, and without any sort of protection, Lars was exposed to the full force of the blast. Just imagine being blown up at point-blank. All the fire, all the force, and whatever shrapnel would have been flying around, that’s what Lars was exposed to. AND HE WAS STILL ALIVE TO FEEL ALL OF IT.
2) The impact.
This happens a fraction of a second after this screenshot, but is still well worth noting. When Lars hit the wall, we could clearly hear a definite ‘crack’ noise. Judging by how he hit the wall, he most likely broke not just his neck, but probably his spine and skull, as well as several other bones, like his ribs or his arms. Along with this, there’s also a good chance that some of his organs may have been ruptured, such as his heart or his lungs. (Especially since the edge of the gem hole would likely have somewhat impaled him on impact.)
This is definitely the moment Lars died, as shown by how his face and body goes completely limp afterwards. But it’s still very likely he felt the agony of the impact for the split second before his death.
3) Lars’ scar.
This is probably the most brutal part of all of this.
As first said by the lovely @bedknees , the fact that Lars’ scarred eye was specifically covered by his hair before resurrection makes it very likely that his head was split open in that spot.
And I completely agree with this.
But how could this have happened? Shrapnel.
One of the reasons bombs are so deadly is not just because of the explosion, but also the resulting shrapnel that would be launched in all directions at anything in range. With Lars being at point-blank range of the explosion, he could’ve easily been exposed to this. And that’s exactly what I think happened.
Why? Because Lars’ scar doesn’t just slice through his cheek and forehead like skimming across a rocky surface may do. Lars’ scar also goes over his eyelid, which is shown whenever he blinks after his resurrection.
So how would’ve this gone down?
I think that a piece of the robanoid’s outer layer, probably sheetlike in shape, was shot through Lars’ head in a fraction of a second, cutting through this eye, skull, and brain, and launching out the other side. AND HE WAS STILL ALIVE TO FEEL THIS.(His hair deliberately covers his eye in this screenshot, in this moment where he is still alive, which probably proves this.)
And you can clearly see Lars’ face twisted in AGONY in the fraction of a second prior to his death.
Lars’ death was not a long, drawn out one, but was still a torturous one. To see just how violent and brutal his death was, it shows just how tragic this moment really is.
Bonus: Other possible scenarios
1) The shrapnel could’ve stopped partway into Lars’ skull, ultimately altering his brain function. (Steven’s magic likely wouldn’t be able to heal where the shrapnel would still be in)
(Although I think this is incredibly unlikely, since Lars is shown to act and function in the same way both before and after death. The areas of the brain that would’ve been affected would impair his speech, his perception of the environment, his motor abilities, his judgement, his emotional reactions, and his sense of self. This would result in a vastly different Lars than the one we know.)
(A similar injury has happened in real life; Phineas Gage. I suggest Googling him)
2) If the shrapnel had been much bigger, it would’ve cleanly cut off a large chunk of Lars’ head in a Mortal Kombat style death.