Annihilus
Welcome to the Negative Zone, where Annihilius is the master and ruler of all things horrible. Just by entering this zone, you’ll feel an immense amount of terror. This is where this evil entity stands and hunger to conquer not just the MCU, but other universes as well, as many as he can get his hand on. Imagine if this evil being made his way down to earth. The world would be a different place. This marvel calls himself the living death that walks and will happily destroy any being that gets in his way of existence. He has agility, reflexes, and stamina like a superhuman (Comic Vine).