The Bored Guardian of Atlantis : "Mermaltis"

Back Story :
Just before the fall of the Island, the last King of Atlantis gathered deep sea Bio luminescent creatures and used their energy to make the last guardian for the purpose to stop any human from discovering the mysterious energy of the realm of the Mediterranean Sea.
Many waves of Pirates and voyagers dared to Find it but no one have returned to tell the adventure. In the age of smartphones. The guardian has become almost unemployed.