New Options:

Disable Commands:
If you want to disable some commands during nightmare, like for example any teleport command, just put the command here, by default and also as an example, I only added the /tp, /spawn, /warp, /home. If the player is currently in Nightmare, they should not be able to use those commands.

Fix Bugs:
There's a dupping bug where, when the server has AngelChest plugin and is enabled, then the "Keep Inventory" is set to true, player's inventory will duplicate upon death. As a temporary fix, if you have the AngelChest plugin, keep inventory won't work even if it is set to true.

Note:
I change the version format from 1.3 to 1.3.1, the other .1 will be for small fix/updates.