You will receive a Master Ball after defeating the Elite Four that you can use, but you might want to save that for more difficult Pokémon such as Landorus,or Kyurem. Zekrom can only be caught in Pokémon White. If you are playing Pokémon Black, you will need to trade for Zekrom.
After beating the Elite Four, activate the glowing statue to descend into the mountain. After a scene, you will be taken to N’s castle.
You can leave the castle if you need to get some more supplies or level your Pokémon up some more. Go to the third room from the right on the third floor of the castle. Talk to the Plasma Grunt and you can be teleported away. When you’re ready to return, talk to the Grunt at the Pokémon Center at the Pokémon League.
Zekrom is weak to Ice, Ground, and Dragon attacks. Since you want to capture Zekrom, you would want to keep his HP low and then go for the capture! If you get it’s health ball into the red, start throwing Ultra Balls at it. Keep chipping away at the health and tossing balls until you catch it. If you fail to capture Zekrom here, you have another chance to do so at the 7th floor of Dragonspiral Tower, which can be found to the north of Icirrus City. [1] X Research source This is where Zekrom can be found in Black 2 once you receive the Dark Stone from N.
