Milsaadi

The Milsaadi are a race of alien assassins in Xenoblade Chronicles X under the Humanoid classification.

Description
''A race of silicon-based organisms not unlike machines. Pain is a sensation that they can disable, thus eliminating any and all fear of battle. They boast remarkable skill in close-range combat, which is why the Ganglion use them to carry out high-profile assassinations. As hunting is regarded as a sacred act, Milsaadi generally confront even the largest of prey armed only with close-quarters weapons. This custom is the reason for their mastery of melee combat, though their hones reflexes also make them excellent Skell pilots.''

On their home planet of Bidwoi, the Milsaadi made up only a fraction of the population-- the majority of which were enslaved aliens that toiled under their totalitarian rule.

Trivia

 * Milsaadi generally don't show their face, though Badul, the One-Eyed is an exception