MidnightMC has multiple custom enchantment plugins, most notably Zenchantments(/ench) and CrazyEnchantments(/ce). Zenchantments adds custom enchantments to the enchanting table allowing you to get so much more customization on your items. You can use /ench info, to see information about any enchantment that you get!
Crazy Enchantments is a more complex but purchasable enchantment plugin. Using /ce, you can access the menu where you can buy a multitude of ingredients used to add enchantments onto your items. Most importantly the enchantment books have multiple rarities including common, rare, and legendary books at the cost of 20, 40, and 60 exp levels.
See Experience Bottles at the bottom of the wiki for more information on the best methods to get enchantments with Crazy Enchants!