Two datapacks for Minecraft 1.21 servers.
PKPack is the quality-of-life pack — extra crafting recipes for dyeing, material conversion, and a few of the conveniences that should arguably be vanilla. Drop it in world/datapacks/ and /reload.
HideAndGoKill is a hunter-versus-hunted PvP minigame. One side hides; the other hunts. Includes scoreboards, role assignment, a respawn queue, and the bookkeeping to run a clean round on a public server without a moderator on duty. Built in mcfunction with command-block scaffolding for the parts that don't fit cleanly into the data-pack model.
Both are public; both work on a stock 1.21 server with no Forge/Fabric.