Zoroark fan Blogs

Unmarked spoiler alert! I'm putting it like this instead of a giant spoiler for the purposes of explanation.

You cannot catch Black Kyurem when you face it in the main story. In fact, the process to get Black Kyurem is a reverse process of what you thought it was - after you conquer the Unova League, go to N's Castle (the Zoroark that was blocking the path on Victory Road will lead the way. Warning if it's a Japanese copy; there's a glitch that could prevent you from ever reaching there, and it was fixed in the localisations so search the Glitches Thread for details) and from there, speak with N and head to where the final battle of Black & White took place. From there, if you choose, you will fight N with his sole Tao Trio Pokémon, Zekrom in your case. It's difficult, as it's Level 70 (I think; I've only been doing Challenge Mode since I completed the game, which has it as Level 75) and you need a bit of training if you want to get your Pokémon to stand a chance against it. Once that is done, the Dragon will turn into its respective Stone for you to take to Dragonspiral Tower to catch at Level 70. Once it is caught, N will inform you that Kyurem has returned to Giant Chasm; from there, you can face it - the level is 75, and it is now catchable. Once Kyurem is caught, you will need to pick up the DNA Splicers after Bianca and Cheren come by and speak a few things. (I haven't reached that point myself yet.) It is from that point that you will be able to use Black (or White) Kyurem, by using the item and selecting the respective Pokémon to fuse together.