Hero skill trainers are a special type of skill trainer found in Guild Wars Nightfall and Guild Wars Eye of the North. A hero skill trainer is easily recognizable by the "[Hero Skills]" suffix in their name in Nightfall; in Eye of the North campaign the four Hero skill trainers have different suffixes. Using a hero skill point to acquire a skill from a hero skill trainer teaches it to that character and unlocks the skill for the game account, effectively allowing access to the skill for all heroes on that account.
If you learn a skill outside of your current professions, they are available when you switch to the appropriate profession.
Unlike ordinary skill trainers, a Hero Skill Trainer does not offer you a skill at all if you have already learnt it, and when offered a skill there is no indication whether its already unlocked.
Hero skill trainer list
For a list of all known hero skill trainers see the hero skill trainer locations page.