Muska

Colonel Muska is a government special agent. He holds Sheeta in custody at the beginning and pursues her during the film with the military.

Muska has light brown hair and hazel eyes. He wears tinted glasses, a brown suit, a white shirt, and a pale yellow cravat. He is armed with what seems to be a Webley Mk VI revolver.

Muska is cold, calculating and duplicitous, and will turn on his allies once he has used them to attain his goals.

Muska is biologically related to Sheeta and a descendant of the royal line of Laputa. He believes that he is entitled to rule Laputa and use it as a powerful weapon to bring the Earth under his control. Unlike the Dola gang, he wants to find the island for the power it will give him.

Sheeta and Pazu use the Aetherium crystal to cast a destruction spell. The light, combined with the giant Aetherium crystal in the roots of Laputa's giant tree, blinds Muska, and he stumbles away as Laputa begins to fall apart. When almost all of the human-made structures on Laputa fall into the sea, Muska can be seen falling along with many of the Laputan robots. It can be presumed that Muska was either killed during the destruction of the Laputan ruins or drowned after he fell.

(Source: Ghibli Wiki, edited)