Hello, I am aware of the fact the empty lands were a suggestion, or a hint, but I am reffering to all the eastern continents which had been separated.
In my opinion, the sun lands or dark lands could be added, as easter eggs, they do not need to be "new" (a biome, mobs and etc...)
however, they could just be a rhun type biome. And since no creature lives there, mobs are not needed.
I also am aware that the empty lands are not canon, since there is no geographical proof to some of them. However, just like harad, it could be added, and could be hidden like meneltarma, and again, as an easter egg.
If there are any problems, I completely understand, this is just a small suggestion to see if its ok.