Ive always been a huge Illager fan! It would be nice if they add all kinds of Illagers from dungeons to minecraft. Maybe they can also add something like different types of bases they acquire where villagers are trapped and then you have to free them.
A portal that you create in the overworld and then when you enter you end up on the same world (overworld) in the same location but everything is gray, all animals are monsters, water is poison,...