Hermes Armor

The Hermes Armor (ヘルメスアーマー) is found in Mega Man X8. It can only be used by equipping the Neutral Armor with all four H-Parts. In addition to the cumulative effects of the four parts, the armor supplies X with the ability to perform the X-Drive, an ability that will boost most of X's stats for a limited time.

Helmet Part, in Avalanche Yeti's stage: Above the boss area. Jump onto the wall before the path narrows down to the boss, and use Zero's double-jump to get past the ledge sticking out above. Then, on the area above, use Shining Ray to melt the ice and make the way to the capsule.
 * This part boosts the charge speed of X's weapons.

Body Part, in Dark Mantis's stage: In one of the stage's two vertical shafts with elevators, instead of going down, make your way up the shaft. There's a hidden room to the right containing the capsule.
 * Enables invincibility to weak enemy attacks.

Arm Part, in Optic Sunflower's stage: While passing through rooms between the "trials", there will be a room with a platform to the left and above blocked by some obstacles. Use Squeeze Bomb to destroy the obstacles; the capsule is on the other side.
 * Charge attacks will be a 3-way spread shot.

Leg Part, in Burn Rooster's stage: The capsule is in plain sight while making your way through the area after the first enemy checkpoint. However, to get to the capsule itself, one must climb a spike-lined shaft climbing upwards. Using Axl's transformation into a Reploid with limited flight (found in the same area) will make this task easier.
 * Boosts speed, and turn invisible/invincible while dashing.