I disagree- the olympus type is a null. The original chart says they have no strengths or weaknesses and I have seen that to be true. That's why Achilles is in with the ADIPPS- the olympus in him has no effect, making him a pure diamond type in battle like Diamond and Infinity.
Almost all the dragons in the game have the same odds against the pure Olympus Dragon. It has no specific vulnerability to any particular color type. Nothing stands out as a preferable opponent.
The Virtue Dragon and Kitsune Dragon, pure pinks, are vulnerable to champs and blacks- especially black/gemstone, black/blue, black/green, black/blue/white hybrids. That is very different than what is seen for the Olympus. If olympus-type was like pink, all three dragons would have the same 'best' opponents. But, they don't.
The sword animation is irrelevant. I'd wager S8 just probably didn't feel like making another magic animation for a color type that only has a handful of dragons.
With olympus hybrids, the other color is what matters. If you look at the suggested opponents for the various olympus hybrids on all the other sites, each dragon has very different results. Those differences directly correspond to their second color type. Pink is not a factor. The only one who behaves like a pink is Aphrodite (olympus/pink hybrid).