Darius Morgan Simp first, human second

Lucius Petronius Fidelis (Luke Pearce)

Lucius (/ˈluːʃ(i)əs/): Roman praenomen, or given name, is said to have been derived from lux, light, and is supposed originally to have been given to children who were born at dawn. Others connect the name with the archaic adjective loucus, which meant "bright" or "shining", pointing out the Greek cognate, leukos, from which the personal name Lucas or Luke is derived.

Petronius (/pɪˈtroʊniəs/): Roman nomen or family name appears to be a patronymic surname derived from the Oscan praenomen Petro or Petrus, meaning "stone, yokel, woodpecker".

Fidelis (/ fɪˈdeːlɪs/): Roman cognomen, from the word fidelis, meaning "faithful".

Gaius Menenius Dārēus (Darius Morgan)

Gaius (/ˈɡaɪəs/): Roman praenomen, or given name, of uncertain meaning. It is possibly derived from Latin gaudere "to rejoice", though it may be of unknown Etruscan origin. This was a very common Roman praenomen. 

Menenius (/meˈnɛːnius/): Roman nomen, or family name, which comes from the root “mens,” meaning “mind” or “intellect.”

Dārēus (/dəˈɹaɪ.əs/): Roman cognomen, or nickname, which traces back to Old Persian: 𐎭𐎠𐎼𐎹𐎺𐎢𐏁 Dārayavauš, which is composed of 𐎭𐎠𐎼𐎹 (Dāraya-, lit. 'to hold') and 𐎺𐎢 (va(h)u-, lit. 'good'), meaning "holding firm the good", "he who holds firm the good(ness)."

Mettius Aurelius Artemis (Artem Wing)

Mettius (/ˈmɛtiəs/): Roman praenomen, or given name, possibly derived from the Oscan word meddix meaning "magistrate". 

Aurelius (/ɔːˈriːliəs/): Roman nomen, or family name that was derived from Latin aureus meaning "golden, gilded". According to some, Aurelius was derived from a Sabine word for the sun.

Artemis (/ˈɑːrtɪmɪs/): In ancient Greek religion and mythology, Artemis is the goddess of the hunt, the wilderness, wild animals, transitions, nature, vegetation, childbirth, care of children, and chastity. In later times, she was identified with Selene, the personification of the Moon. The goddess Diana is her Roman equivalent.

Imperator Caesar Marius Hostilius Augustus (Marius Von Hagen)

Marius (/ˈma.rɪ.ʊs/): Roman nomen or  family name that was derived either from Mars, the name of the Roman god of War, or else from the Latin root mas, maris meaning "male".

Hostilius (/hɔsˈtɪ.lɪ.ʊs/): Roman cognomen that might be derived from hostis, "stranger, foe", but it could possibly have originated as a variation of Faustus, another ancient name meaning “fortunate”.

Gulielmus Albius Strigo (Vyn Richter)

Gulielmus (/ɡʊ.lɪˈɛl.mʊs/): Latinized praenomen or given name that derives from the Germanic Wilhelm (Vilhelm), whose roots wil (“will, desire”) and helm (“helmet, protection”) combine to mean “resolute protector”. 

Albius (/ˈal.bɪ.ʊs/): Roman nomen or family name derived from the common Latin surname Albus, meaning "white".