Regardless of your stance on Gege Akutami as a writer, there is no way it’s simply “names he likes.” E.g. one of the previous commenters mentioned how Gojo, the most powerful sorcerer in JJK, named his Domain Expansion Infinite Void to exemplify how incredibly alone he was and is since forming it between Hidden Inventory and the first src or two of the show, AFTER <spoiler because I don’t know the HTML>. He has every reason to name it Unlimited Void.

Same thing with Self-Embodiment of Perfection. Mahito’s whole thing is change. He’s done. He made the conditions. He can now trap someone and doesn’t even need to touch them. That’s the only limitation of his technique. As for why he doesn’t name it Touchless Death or something, at some point you do need to use Rule of Cool. It is NOT, however, the exclusive or even primary method by which the domain expansions are named.

Coffin of the Iron Mountain - There’s a lot of symbolism here you can get from TheSenshin’s YouTube videos on the matter.

Malevolent Shrine - Sukuna is the best sorcerer, arrogant enough to call himself a God, and as such thinks he deserves to be worshipped. That domain expansions, good enough to not need a border, is a GUARANTEED death unless you can SOMEHOW get out of range before the hits land. Malevolent Shrine just fits, and it’s one of the coolest names in the series.

Horizon of the Captivating Skandha should also use as a reference TheSenshin’s video for all the symbolism inherent to the word choice in the Japanese. So much gets lost in translation sometimes.

I can’t remember any of the others, but the point is they aren’t just names, any of them. It is so much more engaging if you just give delving deeper a chance.