Crystal Eye

Crystal Eye (クリスタルアイ) is Crystal Man's special weapon. It can shoot a large artificial crystal orb. When it hits a wall, it splits into three smaller orbs that bounce about for a while before disappearing. They disappear after hitting an enemy.

Capacity
In Mega Man 5 and Mega Man IV, Crystal Eye uses 1 weapon energy unit. With a full weapon energy gauge, it can be used 28 times in Mega Man 5 and 19 times in Mega Man IV.

Bosses weak against Crystal Eye

 * Mega Man 5: Napalm Man, Dark Man 2, Big Pets
 * Mega Man IV: Napalm Man, Wily Robo Iron Golem (1st form)

Other media
Mega Man uses the Crystal Eye in the Mega Man animated series. In the cartoon it has a large chamber, probably to forge and hold the crystals.