Reroll is a mod designed to completely reroll or reset a player. It will remove their inventory, achievements, etc. and teleport them far away to simulate a completely new world. This is great for hardcore style modpacks that don't want to create new worlds for every reset. It works in single player and on servers.
Feel free to include it in your modpack!
If you would like Reroll to integrate with another mod to reset its data, open an issue describing the mod and what you need to have reset.