Derived from the Latin word "somnī", meaning "sleep". Interestingly, the personfication of sleep ("Hypnos" to the Greeks, "Somnus" to the Romans) was brother to the personfication of death, "Thanatos", which is the name of Somnion's strongest attack. The monster that Yuri must fight to unlock Somnion, Veles, is named after the Czech god of the underworld.