The 22-year old French midfielder recently joined the Black Cats for around £4million from Turkish club Bursaspor and according to O'Neill, is up to the task ahead of his possible debut against West Ham United this weekend.
"He is athletic," the Northern Irishman said. "Of course he is young enough that he can improve his own game and he's got a lot of determination about him.
"I think in time he will definitely improve us. He will give us a bit of extra vitality.
"But he hasn't played in the Premier League before, so it is going to be something new to him, but he is really up for the challenge."