Earlier work of Akasaka Aka, now author of the famous Kaguya-Sama, more than anything Ib: Instant Bullet made me wish he got back to writing serious stuff but with his current experience.

Because this manga is *crazy*. It's a wonderful expression of all the negative emotions of humanity, and a lament for all those who suffer because they're so different from society to be completely incompatible with it even at its most basic level.
And these characters, so deeply broken that they'd rather see the world burn, are chosen as the ones who will save it.

This is everything but the start of a redemption story, because the author takes whatever narrative structure he can and throws it out of the window. It's a manga so chaotic, unfocused, so full with content and themes and just as fast in reaching its conclusion it feels like one long cry of sorrow.
To the very end Instant Bullet keeps defying both common sense and common writing standards just as much as its protagonists defy society.

On some level it reminded me of Kinoko Nasu's Kara no Kyoukai, as they both present characters who are beyond common sense but still playing around its threshold, at times seemingly unsure of which side they want to be on; but it also gave me similar vibes to NisiOisin's Shoujo Fujuubun, with the way the characters were confronting their fate.

This manga is probably too specific in its strengths to ever garner much attention from the majority, especially because of its lack of focus or even direction which could be a huge turn off for most people, but if you liked any of the above stories I'd say give Instant Bullet a try.
But if these things aren't a problem for you, and especially if you are into the whole sheer chaotic madness thing, oh boy you're in for an extremely cool experience.

TLDR: if Akasaka Aka ever makes a longer battle manga similar to Instant Bullet but with added quality from his work with Kaguya it's going to get on my favorites instantly.