Bukkit

Warning: This is for 1.7.2 or older.

You could use this plugin together with heroes, as a Skill. For example a class can use power legendary by clicking with an iron_ingot. Its easy to make that:

1. Edit the config, that the power is perfect for you as a skill for a class
2. Give your class a permissions skill with this permissions: Power.any + <Power.hard/legendary/ultimative> + Power.hard/legendary/ultimative.click>

Example:

permission-skills.yml:

HardPower:
  usage: /power hard
  permissions:
  - power.any 
  - power.hard
  - power.hard.click

part of config.yml:

  Hard:
    Material: LEATHER

and

  hard:
    click: true

part of the heroes-class Gladiator:

permission-skills:
    HardPower:
        level: 5

At this example, all gladiators can use the hard power with /power hard or rightclicking with a leather.