Delta Force: The Special Items Wholesaler

[No female lead, a complicated mix of elements, fairly technical military descriptions, and lots of original worldbuilding]

[The protagonist has no romance, but his younger sister does!]

Delta Force descended upon the world. Some of its items had special effects, while others did not.

But its arrival changed everything!

Totem arrows are useless? Stick one in yourself: either you die or gain a Stand!

A pocket watch is just for telling time? Tell that to my time stop!

What do you mean a blunderbuss became an ancestor launcher? What's Originium Arts?

Before long, all sorts of weirdos appeared in the war zone.

What do you mean Star Platinum is fighting Hermit Purple? Why is Virtuosa standing on the bridge in the middle of a firefight?

At that moment, Hakiye, who was blocking the bridge with “Explosive Dawn,” scratched his head.

“Dunno.”