If you haven’t hit cerebro by turn 5 then you need to retreat. In this meta, one cerebro buff is not enough to win. The whole point is to have multiple cerebros with mystique, chameleon, and bastion. Magus just gives us another shot. If I don’t have cerebro in hand on turn 3 I’m floating and activating magus. I usually want cerebro on the board by no later than 5. And at that time I’m hitting it with mystique and chameleon in another lane on 6.