Who is KSI? He’s quite a prolific YouTube star who regularly uploads FIFA and gaming-related videos. A while ago he started going to game events and even played a part in the Xbox One’s launch event in London. It now appears that his relationship with Microsoft has been severed. The corporate giant has distanced itself after being made aware of his previous behaviour during public gaming expos. Microsoft was not the only big name company who have previously had contact with KSI. EA and BT also have had dealings with him in the past, which begs the question if they really know what KSI is like.