If it's for a rush or mid-game, then Chaos is the way to go; if it's for the late game, then definitely Light.
Ingvar is good for a rush because of his fast start; many believe he's weak in the late game, but I recently came up with a way to play him effectively in the late game.
As for Ingvar in the late game, I can already see you sharing your thoughts, and I'm very interested. Thank you in advance.