DatapacksJava
Just Boss Swords
I don't know my version or loader
Open the Minecraft launcher and look at the profile you play on — it names both, like fabric-loader-1.21.4. The version also shows in the bottom-right corner of the game's main menu.
No loader in the profile name? Then it's plain Minecraft, and these mods won't run — you need Fabric or NeoForge installed first.
Have you ever wanted to use the different boss powers? If so Just Boss Sword is there!
Cosmic Sword (Warden)
You get the cosmic sword by being the first to pick up the dragon egg, but in this state the sword is incomplete. To unleash his full potential, you will need souls...
By killing a warden or a player, you increase the level of the sword by one.
- Lvl 0: Just a very good sword
- Lvl 1: Give you permanently the resistance II and strenght I effects when you hold it in any of your hands
- Lvl 2: When you right click, you do a sonic boom. It deals 5 hearts of damage no mather the armor and has a 1min30 cooldown.
*the listed effects stacks
Give command
Cosmic Sword:
/function jj_cosmic_sword:give/lv<swordLevel(0-2)>
Quick facts
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.21, 1.21.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — see the MC Java Mods guides for the full walkthrough.
Verified by MCModsHub
- Downloads as Just Boss Sword v1.1.0+1.21.1.zip
- Download size: 15 KB
- Download link checked 28 Aug 2026 — working
These come from our own check of the pack file, not from the source page.