Question: Ultra Magnus generally appeared as a chief lieutenant to the leader of what fictional group of sentient robots? 

Context paragraphs:
Floro Dery: Floro Dery is a Filipino illustrator best known for his work as design supervisor of the 1980s "The Transformers" TV series and was the visual creator of "".  He modified the 1984 character models originally designed by Shōhei Kohara and created the 1985 models, all of which became the visual guidelines both for the comic book and the animated cartoon appearances of those characters.  He was also charged with designing all the characters introduced in the movie: Galvatron, Cyclonus, Scourge, Unicron, Ultra Magnus, Hot Rod/Rodimus Prime, Junkions, Quintessons, Springer, Blurr, Wheelie, Kup, and Arcee.  Finally, he designed sets including Unicron (interior and exterior), Autobot City, Cybertron's moons, Hall of Heroes, the Planet of Junk, Quintessa, etc.

List of Transformers: Animated characters: "" is an American animated children's television series produced by Cartoon Network Studios.  It is based on the Transformers toy and entertainment franchise created by Hasbro, about a race of giant, sentient robots that come from the fictional planet Cybertron and are able to change their appearance into cars, planes and other machinery.  Transformers: Animated debuted on Cartoon Network on December 26, 2007, running for three seasons and with the final episode airing on May 23, 2009.  Like most pieces of Transformers fiction, Transformers: Animated focuses on the conflict between two warring factions of Transformer robots, the heroic Autobots and the evil Decepticons, who bring their conflict to Earth.  The following is a list of characters, Autobot, Decepticon and human, who appear in the series.

Ultra Magnus: Ultra Magnus is the name of several fictional characters from the various "Transformers" storylines, generally appearing as a chief lieutenant of Optimus Prime.

Romolo Costa: Romolo Costa (1897–1965) was an Italian film actor who appeared in more than seventy films and television series between 1934 and 1964.  He also worked extensively as a voice actor, dubbing foreign films for release in Italy.  Costa was a character actor who generally appeared in supporting roles. Occasionally he played a more prominent role as in "Il destino in tasca" (1938).

Transformers: Scramble City: Fight!  Super Robot Life-Form Transformers: Scramble City Activation (戦え！超ロボット生命体トランスフォーマー スクランブルシティ発動編 , Tatakae!  Chō Robotto Seimei-Tai Toransufōmā: Sukuranburu Shiti Hatsudō-hen ) , sometimes referred to as just Scramble City (スクランブルシティ , Sukuranburu Shiti ) is an episode of "The Transformers" released as an OVA (Original Video Animation) in Japan in April 1986.  It was created as a promotional video for the new line of 'Scramble City' toys and the cassettes were paired with the toy sets.  Despite strong belief (such as that voiced on the 20th Anniversary DVD bonus commentary for the episode), it was not meant to introduce Japanese audiences to the new characters from (considering Ultra Magnus, Ramhorn, Steeljaw, and Ratbat are the only ones from the film that appear in it).  Chronologically, it takes place years before the movie during the early stages of construction on Autobot City.  But since Trypticon appeared (and was supposed to debut in Five Faces of Darkness), it can be assumed that this video takes place after Alternity.

Turtle-at-Home: Turtle-at-Home, or Selukuki Wohelengh, was a Cherokee warrior and leader, brother and chief lieutenant of Dragging Canoe, a war-chief in the Cherokee–American wars.

Covington Police Department (Kentucky): The Covington, Kentucky Police Department, located in Covington, Kenton County, Kentucky, is charged with law enforcement services for a city of 40,640, encompassing 13.7 sqmi in northern Kenton County.  Led by current Police Chief Colonel Bryan Carter, Assistant Chief Lieutenant Colonel Robert Nader, and Assistant Chief Lieutenant Colonel Brian Steffen.

Autobot: Autobots are a fictional team of sentient robots from the planet Cybertron led by Optimus Prime, and the main protagonists in the fictional universe of the Transformers, a collection of various toys, cartoons, movies, graphic novels, and paperback books first introduced in 1984.  The "Heroic Autobots" are opposed by the Evil Decepticons. Both Autobots and Decepticons are humanoid robots that can transform into machines, vehicles and other familiar mechanical objects.  Autobots typically transform into regular cars, trucks, or other road vehicles ("auto"mobiles) but some few are aircraft, military vehicles, communication devices, weapons, and even robotic animals.  These Autobots are often grouped into special "teams" that have the suffix "-bot" at the end, such as in Dino"bot" (Decepticon groups' names end in "-con").

Optimus Prime: Optimus Prime is a fictional character from the "Transformers" franchise.  He is the leader of the Autobots.  A fictional group of sentient robots that can transform into other forms (e.g: cars and other objects) He is the most iconic of the Transformers, being frequently featured in Popular Culture.

Magnus, Robot Fighter: Magnus, Robot Fighter is a fictional comic book superhero created by writer/artist Russ Manning in 1963.  Magnus first appeared in "Magnus Robot Fighter 4000 A.D." #1, published by Gold Key Comics in February 1963.  The character was subsequently published by Valiant Comics and Acclaim Comics in the 1990s, and was reintroduced by Dark Horse Comics in August 2010.  In every incarnation, Magnus is a human who battles rogue robots in the year 4000, though some aspects of the concept have varied with each publisher.

Supporting paragraphs: Ultra Magnus Optimus Prime
Answer: Autobots