Father Leo Cosmas Fortiter is the human form of Ultraman Lugeno. He is tall, frail looking old man, who always wears his cassock, except when he swims, because he is a member of the Tradition Rite of the Roman Catholic Church. He is slightly eccentric: he says all his prayers in Latin, and chants half the Office which all Catholic Priests recite daily. He is one of the only known keepers of the Great Names.
- Mind Power: Father Leo has great mind power; he has shielded buildings from blows and beams while in human form and teleported past doors or through walls. He can move objects or kill weak minded people.
- Silver Bullets: He can raise his hand and silver bullets will materialize around him, barraging an opponent.
- Shockwave: His human form can generate a small shock-wave strong enough to knock a human down.
- Healing: Father Leo can use his mind to heal wounds in others.
- Memory: Father Leo, due to his ultimate nature, can memorize incredible amounts of data, including the entire Holy Office, Proper and Common of the Mass, the Bible, the Suma, the Imitation of Christ, the Lord of the Rings and other written works, as well as numerous operas. He knows incredible amounts of scientific and historical data, and knows almost every study resource from memory, whether completed by a human or another alien. If there is something he does not know, he can use his mind to find out something about it. In fact, he is the most reliable resource in any matter pertaining to any science, skill, species, or historical question.
- Strength: His body is incredibly strong, particularly when compared to a human's. He is strong enough to lift a truck, throw a refrigerator or break through a wall.
- Agility: He can move very quickly, jumping, dodging, rolling, ducking, swimming, running, climbing or even swing on branches or vines, far faster and much longer and further than any regular human could.
- Mind-reading and telepathy: Father Leo can read one's mind if one is unaware of him, weak-minded, wounded or emotional, and can detect all but the most obscured telepathic signals. Most ultras cannot communicate without him being able to hear the communications.
Likes: Classical music, opera, chant, masses, folk music, Divine Office, books, science, hot food, fire, water, insects, Kamen Riders, LOTR, Star Wars, art and chess.
Dislikes: Metal, rap, cold, cussing, Wagner, Harry Potter, people more arrogant than himself.
- Leo is a reference to Saint Leo the Great, who according to Catholic belief, stopped Attila the Hun at the very gates of Rome. Cosmas is a reference to St. Cosmas, but also a pun for "Cosmos," making his name a double pun for two other ultramen. Fortiter is the Latin adjective meaning "bravely, strongly."
- His name, coming from one of the greatest popes of Church history, as well as his position as a priest, signifies Lugeno's role in Argentium.
- Unlike Jake Miliken or Madame Kandakai, Leo is the human form of an Ultra as opposed to a host: he is not two fused lives but only one person.