How do you use the splicer in black 2?

In Pokémon Black 2, the Splicer is used to combine the forms of the Pokémon Reshiram and Zekrom. To use the Splicer, you must first have both Pokémon in your possession. Once you have them, go to the appropriate location, typically the Dreamyard, and select the Splicer from your bag to fuse them into their respective forms, allowing you to access their unique abilities and moves. After the fusion, you can revert them back to their original forms using the Splicer again.