It's called Rappenem's Reforge and you can download it right now on CurseForge and Modrinth! It's currently for 1.21.5 only, but I plan on making it compatible with a few other versions of the game soon :D
My goal with this pack is to eventually resprite most of the game's assets which will include items, blocks, UI and more! It's currently in Beta and there's still a lot more work to be done, so I hope you guys will stick around to see my progress on this pack ^^