Satan doesn't need a candidate in every generation. Although only God knows the day and hour Satan has a much better understanding of God's word than Christians, and he is well aware of the times and seasons. The unclean spirits asked Christ if he had come to torment them before the appointed time. They know that a time is appointed, and probably have a pretty good idea of when that time is. We should also see the anti-christ reign as an ongoing plan of Satan. Perhaps it is a plan he has been trying to implement for generations, (remember Hitler?).
In any event, Satan is the great countefeiter. I believe his relationship with the anti-christ will be an imitation of the relationship between God and Jesus. Since several events in the life of the anti-christ are imitations of Christ (deadly wound that was healed etc.) then perhaps we can expect to see many other similarities in the life of the anti-christ... A supernatural birth, miracles, perhaps even an age similarity. Since Jesus was about 30 when he began his ministry perhaps the anti-christ will be about the same age when he begins his journey.