The night tower is ruled over by the demon king. Many have entered to plunder his riches, slay the mighty king, or appeal to him, though none have left. Not for reasons your thinking, though...
They've all been transformed by the king to be more... *Suitable*... I.e.: they all turned into female things (demons, anthro snakes, dragons, ECT.*
*Surprisingly, the demon king isn't *that* evil. Sure he is not good, but he isn't cruel. He transforms those who enter his Night tower, but never hurts them