Question: Writer Bill Coffin made contributions to several of Palldium's game series, including the book Heroes Unlimited, written by who?

Context paragraphs:
Systems Failure: Systems Failure is a role-playing game written by Bill Coffin and published by Palladium Books in July 1999.

Dream (comics): Dream is a fictional character appearing in American comic books published by DC Comics' imprint Vertigo.  The character is the protagonist of the comic book series "The Sandman", written by Neil Gaiman.  One of the seven Endless, inconceivably powerful beings older and greater than gods, Dream is both lord and personification of all dreams and stories, all that is not in reality (which, in turn, Dream may define by his existence).  He has taken many names, including Morpheus and Oneiros, and his appearance can change depending on the person who is seeing him.  Dream was named the sixth-greatest comic book character by "Empire Magazine".  He was also named fifteenth in IGN's 100 Top Comic Book Heroes list.

HeroClix: HeroClix is a collectible miniatures game that uses the Clix system that centers on the world of superhero comic books, especially the Marvel and DC Comics universes.  Players construct teams of comic book heroes, villains, or characters from various video games series such as Street Fighter, Gears of War, and Halo and engage in a turn-by-turn battle on grid maps based on various storyline locations.  The game was originally designed and produced by WizKids, but was discontinued in November 2008 when WizKids owner Topps shut down their HeroClix line.  In September 2009, collectible toy producer National Entertainment Collectibles Association (NECA) purchased some of the WizKids' intellectual property from Topps, including the HeroClix rights and then soon after began to produce and sell new HeroClix series.

Hagibis: Hagibis (meaning "rapidity", "velocity", or "speed" in Tagalog) is one of the first comic book heroes in the history of komiks in the Philippines.  Hagibis was created in 1947 by Francisco V. Coching, a Filipino comic book artist and illustrator who is considered as the “father" or "grandfather” of Filipino komiks.  Tarzan-like in appearance, the form of Hagibis had also been based on another early Filipino comic book hero, namely Kulafu who was created by another pioneer Filipino comic book artist, Francisco Reyes.  Hagibis became one of the longest running serials in the history of Filipino comic books, which was featured for fifteen years in the pages of "Liwayway" magazine.  An example story about Hagibis that appeared in "Liwayway" magazine was "Si Hagibis sa Ibang Daigdig" (Hagibis in Another World).  Sequels in komiks to the Hagibis series were "Anak ni Hagibis" (Child of Hagibis) and "Si Gat Sibasib" (Gat Sibasib).  Hagibis was later made into a movie with Fernando Poe, Sr. acting as Hagibis.

Adelbert Ames Jr.: Adelbert Ames Jr. (August 19, 1880 – July 3, 1955) was an American scientist who made contributions to physics, physiology, ophthalmology, psychology, and philosophy.  He pioneered the study of physiological optics at Dartmouth College, serving as a research professor, then as director of research at the Dartmouth Eye Institute.  He conducted important research into aspects of binocular vision, including cyclophoria and aniseikonia.  Ames is perhaps best known for constructing illusions of visual perception, most notably the Ames room and the Ames window.  He was a leading light in the Transactionalist School of psychology and also made contributions to social psychology.

Bill Coffin: Bill Coffin is a writer of novels and role-playing games in the fantasy and science fiction genres.  Perhaps best known for his work at Palladium Books from July 1998 through May 2002, he made significant contributions to several of Palladium's game series, most notably "Palladium Fantasy", but also "Heroes Unlimited" and "Rifts", and created his own game, "Systems Failure".

Heroes for My Daughter: Heroes for My Daughter is a non-fiction book written by Brad Meltzer.  It contains a series of vignettes on inspiring heroes - famous and lesser known - whose stories Brad wanted to share with his daughter.  It is the follow-up to the bestselling book Heroes for My Son.  According to WorldCat, the book is in 558 libraries.

Will Jacobs: Will Jacobs (born 1955) is an American comics and humor writer.  He was a coauthor with Gerard Jones on "The Beaver Papers", "The Comic Book Heroes", and the comic book "The Trouble with Girls" (1987–1993).  He was a contributor to "National Lampoon magazine" and various DC Comics.  Jacobs left professional writing in the 1990s to start a used and antiquarian book service, Avalon Books.  He co-wrote with Jones "The Comic Book Heroes", a book dedicated to the history of the American comic book industry from the Silver Age to the present.

Heroes Unlimited: Heroes Unlimited is a superhero role-playing game written by Kevin Siembieda and first published by Palladium Books in 1984.  The game is based upon the Palladium Books Megaversal system and is compatible with other games that use the Palladium system.

Action Comics 1: "Action Comics" #1 (June 1938) is the first issue of the original run of the comic book series "Action Comics".  It features the first appearance of several comic book heroes—most notably the Jerry Siegel and Joe Shuster creation, Superman.  For this reason it is widely considered both the beginning of the superhero genre and the most valuable comic book of all time.

Supporting paragraphs: Bill Coffin Heroes Unlimited
Answer: Kevin Siembieda