@Nexus75 - The character must be trained in Intimidate to gain the benefit. If so, then a rattling attack gives the target a -2 penalty to attack rolls until the end of the character's next turn (as long as the target isn't immune to fear effects). I can't remember if it requires that the attack hits.
@Nexus75 - If the character has power points (usually from a psionic class or theme), then those points can be spent to augment the weapon's power in the stated manner. (If my answer doesn't make things clear for you, I'll go into more detail.)