Thatch

Sachi (サッチ, Satchi) was the commander of the 4th Division of the Whitebeard Pirates.

It was revealed that in Chapter 440, Sachi had a devil fruit that Blackbeard was after. This Devil Fruit was the very reason that Blackbeard joined the Whitbeard Pirates, so he killed Sachi and ran off with the Devil Fruit.

Nothing else is currently known about Sachi.