The Pulse Tract is one of the 3 forbidden tomes in the videogame Shadow Hearts. The book has the power to manipulate the elemental forces of nature and manifest the planet's life-force.
History
The Pulse Tract is book of rituals, spells and alchemical formulas penned by Roger Bacon in the 12th century, and stored in the Vatican for many years. In the late 18th century, the Pulse Tract was stolen long with it's sister books the Émigré Manuscript and the Codex of R'lyeh by a former student of Bacon's named Albert SImon. Albert, a former Cardinal of the Catholic Church, had broken into the Vatican on behalf of a man named Patrick Heyworth to steal the Émigré Manuscript only but Albert had his own plans for all 3 books. Albert read all three books and the gained revelations to make himself the most powerful warlock on the face of the planet. After Albert read over the books, he delivered the Émigré Manuscript as promised to Patrick who wanted to use the book to resurrect his wife Elaine.
The Reverse Demons' Gate Invocation
Albert heard about a man named Dehuai who was a powerful Taoist sage in China that had nearly summoned an incarnation of hell into the world but was defeated by a man named Jinpachiro “Ben” Hyuga, who was a Harmonixer, a human with the power to merge with demons and took over their forms. Not only had Ben stopped Dehuai's ritual, though at the cost of his own life, he had torn apart half of Dehuai's body to get to the demonic entity Dehuai tried to summon. Since the ominious "Demon's Gate Invocation" Dehuai had shut himself off in his tower to recover, until he was contacted by "Roger Bacon". Albert used the name of his mentor to hide from some of the people hunting him down for stealing the books and to garner the prestige the name gave him from other mystics and so when Albert Simon introduced himself to Dehaui, it was as Roger Bacon. "Bacon" told Dehuai he admired his works and wanted to pay him tribute and gave Dehuai the Pulse Tract, a quick read through of the Pulse Tract's secrets made Dehuai think "Bacon" did not know what he was giving away and he happily accepted the gift.
With the Pulse Tract in his possession, Dehuai renewed his attempts at a ritual to summon an entity into the world under his power and spent ten years studying it fully. Pulse Tract stated Dehuai would need a being with ties to the divine to catalyze his ritual. "Bacon" knew of such a person Alice Elliot, the daughter of the priest hunting him down for stealing the books. "Roger Bacon" killed Father Elliot and pursued Alice, as he was closing in on her though "Bacon" was held off by a young man named Yuri Hyuga who was a Harmonixer and Ben Hyuga's son. After Yuri escaped with Alice from "Bacon's" initial attack "Bacon" reported the interference of the young Harmonixer to Dehuai. Though "Bacon" offered to make it up to Dehuai by going back and capturing Alice and doing away with Yuri himself Dehuai refused, opting to do it himself with a chance to get revenge on his old enemy and capture the means to reactivate his ritual at the same time. Eventually Dehuai does kidnap Alice and does use her to catalyze his ritual, Yuri saves Alice but not in time to stop the rites and fights Dehuai to stop him, upon fighting Yuri, Dehuai admits the ritual is not the same as his last one but a "Reverse Demon's Gate Invocation" meaning the Pulse Tract allowed him to incarante an angel that was the manfestation of the planet's life force under his command. Yuri beats Dehuai to within an inch of his life but Dehuai uses his dying breath to pour his life-force into the ritual and....nothing happened. As it turned out the Pulse Tract's rites, while comprehensive to Dehuai as a master summoner, were far beyond his capacity to actually use. At the last moment "Bacon" arrived and activated the ritual himself revealing to Yuri and friends that he was not Dehuai's gofer but in fact had played Dehuai into doing all the work for him. Once activated the Pulse Tract's Reverse Demon's Gate Invocation summoned the obscenely powerful Seraphic Radiance.
Towards the end of the game, Yuri will corner Albert in his final rites using the Codex of R'lyeh. Albert tells Yuri he had not stolen the books for simple spells and was looking to use the books' reality warping power to remake the world as a utopia, with the secrets for such a feat located in the Codex of R'lyeh. Albert was insightful enough to know that using dark magics dosen't always yield their desired results and so he tested out the books. For the Émigré Manuscript he had used Patrick and later Jack while for the Pusle Tract he had high hopes for Dehuai's technique and so as it tuned out Dehuai's Reverse Demons' Gate Invocation was just a smaller version of the rites Albert was really intending to perform.
Getting the Seraphic Radiance Fusion
Towards the end of the game, the Pulse Tract can be gained as part of the sidequest to get the game's good ending. If the player recovers the Émigré Manuscript from Jack's orphanage and reads it they will be made aware of a dungeon called the Cave Temple, After finding a way through the winding maze and getting the book at the end Yuri gets the Pulse Tract from Roger and uses it to resummon the Seraphic Radiance, upon defeating the creature, Yuri merges with it and gets his most powerful Fusion.