You'll need a Misdreavus first, go to Eterna Forest and find one. Then, go to Veilstone City Galactic Warehouse. Where you teamed up with Dawn/Lucas to fight Team Galactic, because Dawn/Lucas lost her/his pokedex. You go inside, there is a door blocking your way. But eventually you will find you way to it, and there you can find a dusk stone.
Use dusk stone to evolve Misdreavus into Mismagius.
Hope I helped.
Unfortunately, you cannot catch Mismagius, you must evolve it from Misdreavus. You can catch Misdreavus in Eterna Forest at night on Pokemon pearl, or on any of the floors in the Lost tower just outside Solaceon Town. In all of these places it is quite rare and will take some time to find. However, don't give up if you can't find it straight away as it should appear within 1/2 an hour at the worst. I recommend using dusk balls on it when it does appear. To evolve it to Mismagius you must use the Dusk Stone found in the Galactic Warehouse in Veilstone City. (The big Galactic Warehouse!)
Hope this helped :)
No, mismagius was not created in the time of that game. You can catch a misdreavus though.
No, it is exclusive to Pokemon White. Where you would catch Rufflet in White, you catch Vullaby in Black.
In Pokemon black you catch RESHIRAM and TORNADUS In Pokemon white you catch ZEKROM and THUNDERUS Sources : myself
you cant catch rayquaza in Pokemon black
You cannot catch a Rhydon in Black and White. You have to catch a Rhyhorn and level it up to level 42. Rhyhorn is only available in Pokemon White in White Forest.
No, mismagius was not created in the time of that game. You can catch a misdreavus though.
Mismagius cannot be caught in platinum.
No, it is exclusive to Pokemon White. Where you would catch Rufflet in White, you catch Vullaby in Black.
In Pokemon black you catch RESHIRAM and TORNADUS In Pokemon white you catch ZEKROM and THUNDERUS Sources : myself
You can't catch it in Black, but you can catch it in White. In the White Forest.
You can not catch Braviary. You have to catch Rufflet in Pokemon White and evolve it.
It is exclusive to Pokemon White, you can't catch it in Pokemon Black. You would need to trade with someone who has white.
you cant catch rayquaza in Pokemon black
You cannot catch Thundurus in Pokemon Black, he is exclusive to Pokemon White.
You can't catch it in Pokemon Black. You'll need to trade for it from Pokemon White.
In black you can catch Reshiram and tornados. In white you can catch Zekrom and thunderos.
you have to get in Pokemon white