The enchantments attribute is used to apply enchantments to items made using MythicMobs. Any of these can be put on any item and can exceed natural enchantment-level limits set by Minecraft. Some enchantments may not have any effects if put on items that they weren't made for.
internal_itemname: Id: <material> Enchantments: - <enchantment>:<level> - <enchantment>:<level> - ...
Type of enchantment to be applied to the specified item.
The level of the specified enchantment.
lethal_pickaxe: Id: diamond_pickaxe Enchantments: - DAMAGE_ALL:3 - KNOCKBACK:1
A list of available enchantments can be found on spigot javadocs