Lusamine should join this guide

Wouldn't have been simplier to go to Sinnoh, catch one of the two Space/Time dragons(Giratina has its own world, and isn't much good at creating new universes), and then create another alternative world with only Nihilego and you present?

Bam! Now you have your room in which you two can do whaaaateeeever you want. coughtentaclescough