First of the Pokemon Black and White legendaries is #494 Victini. Victini is a Psychic/Fire Pokemon. Unlike most other Pokemon, Victini has very uniform stats. Each base stat is 100, making a stat total of 600. While this is weaker than some of the other Pokemon Black and White legendaries, Victini can be caught early under the right circumstances, and it be used to beat down the gym leaders easily.
Unfortunately, unless you act before April 10, 2011, it will be impossible to catch Victini. You need to get Liberty Pass item from WiFi with Mystery Gift and then go to the boat in Castelia City. After this time, all you can do is trade for Victini.
Cobalion is part of a trinity, and the first you have to capture to get the other two. Cobalion is a Steel/Fighting Pokemon and has these base stats:
Special Attack: 90
Special Defense: 72
To find Cobalion, just go through the maze in Mistralton Cave. At the end of the cave, Cobalion will stand there, waiting to battle you.
Terrakion is a Rock/Fighting Pokemon and is the second in this trinity. It can be gotten after capturing Cobalion. Its base stats are about the same as Cobalion, just the Attack and Defense are switched, so are Special Attack and Special Defense.
After capturing Cobalion, a cave will open at the top of Victory Road. Go through this maze and fight and catch Terrakion.
Virizion is the last in this trinity and is a Grass/Fighting legendary. It has the same stats as Cobalion, but the Defense and Special Defense are switched. Virizion can be captured after getting Cobalion, but you don’t need to get Terrakion.
Go to Pinwheel Forest and search the east side. There you will find Virizion waiting for you.
Tornadus and Thundurus
Aside from their elements, Tornadus and Thundurus are exactly the same, and are part of the kami trio. The kami trio consists of Thundurus, Tornadus, and Landorus, and the three are meant to control the weather. They both have the exact same stats:
Special Attack: 125
Special Defense: 80
They are both also captured in the same way. After getting the eight badges, go to Route 10 and after being told about some weird weather, go to a house in Route 7. A woman will tell you a story, then these Pokemon will roam around Unova.
The only difference is that Tornadus is a Flying Pokemon and is only captured in Pokemon Black, while Thundrus is captured in Pokemon White and is an Electric/Flying Pokemon.
Landorus is a Ground/Flying Pokemon, and is part of a trinity that involves Tornadus and Thundurus. Landorus can only be captured if you have the other two Pokemon, which are available only through trading.
Landorus has these base stats:
Special Attack: 115
Special Defense: 80
After getting Thundurus and Tornadus, bring both of them to the Abundant Shrine on Route 14, and Landorus will attack.
Reshiram and Zekrom
Much like Thundurus and Tornadus, Reshiram and Zekrom (which are on the front of the cover) are captured at the same place and in the same way. Both of them, along with Kyurem, make the Tao trio. The Tao trio represent yin, yang, and the center. Zekrom is only available in Pokemon White and is a Dragon/Electric Pokemon. Reshiram is available in Pokemon Black and is a Dragon/Fire Pokemon.
Reshiram’s stats are:
Special Attack: 150
Special Defense: 120
Zekrom has the same stats, just his Attack and Defense are switched with Reshiram’s Special Attack and Defense.
You have two chances to catch one of these Pokemon. The first is at the end of N’s Castle after beating the Elite Four, and the second is at Dragonspire Tower if you didn’t catch one of them the first time.
Kyurem is in a trinity with Zekrom and Reshiram, but it caught in a completely different way. Kyurem is a Dragon/Ice Pokemon and has these stats:
Special Attack: 130
Special Defense: 90
Kyurem is found on Route 13 in an area called the Great Chasm. Towards the north, in a cave, Kyurem waits to challenge you.