Better herobrine mod is a work-in-progress mod that implements herobrine into the game with a lot more features!
Herobrine has a chance of spawning in your world. when you kill him he will drop a herobrine gem. you can use it to craft legendary tools and armour. herobrine gems can also be found as ores
The crafting recipies are simple. kill herobrine to get gems, then craft tools and armour with the default recipies.