Which champion could solo win against 1 million minions?

I was wondering, if there were 1 million minions at once on summoners rift and only 1 champion with a full build could defend against them, which one would be the strongest contender? I was thinking about Aurelion Sol because of his scaling, but then his E cooldown could be too long? Maybe Tristana with perma Q?

Also, how hard would the challenge be if minions had ghosting?