Bukkit

Disclaimer
SkillAPI is released under the MIT license and the original author has not updated his work in almost 2 years now. My team and I are continuing the development of this plugin.

Moving Forward
Proskillapi is based on the original Skillapi forked by Sentropic.

Wiki | Discord | Issues | Suggestions | Editor | Javadocs

Dependency Plugin (required)
You can download it here.

Some of PROSKILLAPI's Features

• Cross server support with MySQL
• Most powerful online editor of any skill creation plugin on Spigot!
  • Create up to 16 triggers that activate skills like
  • Set up to 9 targeters like Area, Cone, Linear, Self, etc
  • Set up to 37 conditions to check for before a skill will activate like armor checks, chance, skill level, health, etc.
  • Set up to 76 mechanics that give your skills their abilities
  • There are literally millions of possibilities for creating your custom skills.
• Create unlimited groups like class, race, etc.
• Create separate names for mana for each class.
• Set the mana regen speed for each class.
• Create custom attributes like Stregnth, Vitality, Wisdom, etc.
• Multiple sources for gaining experience like from mobs, block break, block place, craft, experience bottles, etc.
• Set beginning stats for classes like health, mana and other attributes.
• Set list of skills available per class.
• Create custom gui menus for selecting classes, allocating attribute points, skill points, etc.
• You can create classes with subclasses.
• Limit with restrictions to what items are unusable per class.
• API for developers to hook into.
• Multiple casting options with skill bars, click combos and more
• Create RPG style attributes, class requirements and more
• Customize/change any command to suit your needs.
• Full permission control for almost every feature.
• Allow players to switch/create multiple accounts from 1 minecraft account. Also controlled with permissions.
• Allow players to downgrade stats like skills and attributes.
• Custom model data support for resource pack makers.
• Set blocks to ignore from skills explosions
• Check for class, level and attribute restrictions in item's lore (works on any custom items from any plugin)
• Set to drop items if they don't have the correct levels, class, etc
• Set inventory slots that are checked for bonuses.
• PlaceholderAPI support with lots of built in placeholders that can be used on any plugin's menus that support papi.
• Optional title messages for leveling up.
• Multiple casting options including click combos and target visuals using particles to show you the direction your skills will be cast.
• Set list of worlds that skills will not work in.
• and a lot more!

Chinese translation of the editor: https://skillapi.ods.im/