Considering that Mewtwo, and other Psychics are using Ghost/Psychic/Dark moves, having a Dark resist is very useful. Plus many legendaries are part Psychic, so taking only 39% damage from Psychic attacks is pretty good, as well as 62.5% from Dark and Ghost types. Dark Pulse is 2 bars as a charge move, so I could see it getting hits in on Mewtwo, etc. before their Focus Blasts would hit.
It was, but they gave it to something else, so it was for a time. They might not, but with Castform and Deoxys forms implemented, they likely will. Castform's form change, like Greninja, is based on an ability afterall.
I think its 2 years for Greninja, and 3 years for Primarina, if its 1 generation per year as it has been (and since its been 2 years and 4 generations in, it might be faster).
No, when people mentioned the best Water type, they didn't say in the next few months, they meant overall. Swampert getting it is speculation too. We were just saying what might surpass Kyogre, since Swampert > Feraligatr, and people thought that would be the closest thing.
2 Years is a bit away, but not several years. We are Gen 4, and in 2 years is Gen 6.
I don't see a way of finding out Ash-Greninja's Attack, as this chart lists CP but not the Attack stats for Greninja-Ash *even though it lists others* (and was before the HP / Def shift). Attack shouldn't be impacted by the shift, but even frail Pokemon like Gengar gained like 25% more durability, so Ash-Greninja's CP would be higher as Gengar's was raised.
https://pokemongo.gamepress.gg/max-cp
Also, CP isn't everything, otherwise people wouldn't bother with things like Gengar for their teams, and only opt for 3.5K + CP Pokemon. Look at Venusaur, look at Roserade, look at Electivire.