The skill "Call to Greatness" has a different effect depending on the class of the target it is cast on. When you learn this skill, you should familiarize yourself with all the effects before trying to use it in combat, so you know what your doing to your target and can give them a heads up. Here are the effects:

• Burglers: +15% damage to positional attack skills. Surprise Strike is recovered every 5 seconds.
• Captains: Grants a defeat event. Grants the Battle-readied state every 5 seconds. That means captains have access to some of their more powerful skills (group heals, attack speed and parry buffs, etc.) that normally only open up only after an enemy defeat.
• Lore-masters: −3% chance for enemies to resist Blinding Flash. Recovers Blinding Flash every 5 seconds.
• Minstrels: +10% to healing done. Recovers Chord of Salvation every 5 seconds.
• Guardians: +25% threat generation. Grants the Guardian's Ward effect every 5 seconds.
• Champions: Grants a defeat event and 2 Fervor. Grants 1 Fervour every 5 seconds.
• Hunters: −10% threat generation and grants 3 Focus. Grants 2 Focus every 5 seconds.
• Rune-keepers: Grants an in-combat power regeneration boost.
• Wardens: Grants 10% threat generation. Grants 5% damage increase.