Dark Dimension

I really think, and hear me out on this, we need like an opposite Dimension in Minecraft, so what I'm thinking is you make a portal and once you travel too it, all the chunks you've already been too in the normal world will be turned into some sort of oppisite darkness. So like say you build a wood house, in the Opposite Dimension or Dark Dimension there would be dark wood, built exactly the way you did, also in this dimension I'm thinking creepers, zombies, spiders and skeletons don't attack you but sheeps, pigs, cows and chickens do. Also with the whole chunks thing, lets say you want to bring back dark wood from your house in the normal world back too the normal world, if you destroyed your house in the Dark Dimension/Oppisite Dimension in the reall world you would destory it. This would be great because it would add many many new blocks, a new challenge and more bosses that could be gotten, let me know what you think in the comment and can anyone tell me if theres a mod that already does something like this, I just think it would be really cool if they added it into vanilla minecraft. Imagine the possibilites, who knows one of the bosses could be a dark version of you that uses whatever armour you have on at the moment and the tool you have.