How do you merge Pokèmon other than Kyurem and Reshiram/Zekrom?

Question

And also, can I put it in my Black 2 game?

Answer 1

the only Pokemon you can merge are kyurem and reshiram/zekrom
its possible in older games such as yellow to do a glitch that merges Pokemon stats with diferents sprites and moves such as a golems def with a ninetails attacks... also known as the Q glitch
cant be traded though

Answer 2

You cant, only Kyurem and Zekrom/Reshiram can fuse together.