Erm the entire game played differently than it did in the first season, with card having different effects as well - making the first season complete bunk here (and all toon cards AND relinquished especially). off the top of my head (as well as your examples) we had unique cards in the cyber wars, diffusion wave motion in the movie?
While we're on slifer, as far as I'm aware in the series not only did he have his hand based scaling that remained intact - he also took 2000 atk/def off EVERYTHING that your opponent summoned, rather than just face up atk specials (which can be played around very easily.
Lastly chaos emperor dragon is valid, but isn't it also banned in nearly every format anyway? You wouldn't even be allowed to play that at my local card store.