Welcome!
This mod simply does what it says, it adds Herobrine's stone sword from Animation Life (Created by Squared Media)
The sword is not available from the Creative menu, but you can summon it by command.
UPDATE In version 1.2.0 of the mod, if you right-click with the sword, it summons lightning where you look to a distance up to 80 blocks.
Both Fabric and Forge versions are available in the Files category :D
You can request other versions in the comments ;)
Watch Animation Life by Squared Media here.
How to craft the Reinforced Diamond for the sword
The crafting of Herobrine's Sword, it can be repaired using cobblestone
If there are any bugs or problems about the mod, feel free to leave a comment and I'll respond as fast as i can ;)