From Frank Herbert's Dune Chronicles:

Of the Atreides line. Known as 'The Bashar'. Miles Teg was the commander of the Bene Gesserit armies under Reverend Mother Taraza. He served the Bene Gesserit to his death on the planet Rakis (formerly Arrakis). He was also trained as a Mentat. Like Paul, his mother was Bene Gesserit and trained him to be able to defy the Voice as well as imprinting.

Near the end of his life he discovered some latent special (seemingly magical) abilities. While he was not prescient as earlier Atreides were, he was aware of No-Ships(Ships that were invisible both to the electromagnetic spectrum and to prescient individuals) even at great distances. He kept knowledge of this ability from his Bene Gesserit Masters for fear that they might mistake it for prescience and kill him to prevent a recurrence of the Kwisatz Haderach.He could also move far faster than is normally humanly possible. When he first discovered this ability, while on the formerly Harkonen planet Gammu (aka Geidi Prime), he killed an entire office building worth of people (Honored Matres included) before any of them had a chance to defend themselves. Afterward, he discovered that such action was accompanied by ravenous hunger as his body consumed all of its available resources at an alarming rate. Apparently the speed was related to his body being able to act at a much higher level of efficiency, as a result his blood was hyper-saturated with oxygen and looked black.

He served again under Darwi Odrade who brought him back as a Ghola. In his ghola child's body his special ability to move with great speed was severely limited by his body's smaller energy store.

Teg appeared in books 5 (Heretics of Dune) and 6 (Chapterhouse Dune).