Looking for a resource like this: http://bukkit.org/threads/nmsdamage.186895/#post-1936462 What's wrong with that one, you may ask. Well, the pastebin it links to is deleted.
The Bukkit ones? A hundred times. All of them. If you mean an API that works like the resource in main post? Sure.
@Anrza You can use this: http://jd.bukkit.org/org/bukkit/entity/Damageable.html#damage(double, org.bukkit.entity.Entity) or this http://jd.bukkit.org/org/bukkit/eve...ity.EntityDamageEvent.DamageModifier, double)