Download the plugin for 1.17+ here (deprecated for 1.20.4+).

This plugin adds two items that you can use against mobs or players. The plugin can be used with the permission node oppoweritems.oppoweritem. The commands are subcommands of the command /oppoweritem or its aliases. This is the first plugin I'm publicly releasing, so it might not be optimized the best. I tested it a lot, though, and I recommend you try some of the power items.

More details about the items