"Slayers Great" is a four-episode OVA series that serves as a prequel to the main "Slayers" storyline, offering insight into the early adventures of Lina Inverse and her companions. The narrative begins with Lina and her loyal companion, Gourry Gabriev, traveling to the town of Mipross to investigate rumors of a powerful magical artifact known as the Claire Bible Manuscripts. These manuscripts are said to contain ancient knowledge capable of granting immense power, making them a target for various factions.

Upon arriving in Mipross, Lina and Gourry encounter a young girl named Raltark, who is being pursued by a group of mysterious assailants. Raltark possesses a fragment of the Claire Bible Manuscripts, which she inherited from her father, a renowned archaeologist. The assailants, led by the enigmatic sorcerer Rezo the Red Priest, seek the manuscript to unlock its secrets for their own nefarious purposes. Rezo, a recurring antagonist in the "Slayers" universe, is depicted here in his earlier years, showcasing his cunning and ambition.

As the story unfolds, Lina and Gourry form an uneasy alliance with Raltark to protect the manuscript and prevent it from falling into Rezo's hands. The trio faces numerous challenges, including battles with powerful monsters, traps set by Rezo's followers, and the moral dilemmas surrounding the use of the manuscript's knowledge. The narrative explores themes of trust, sacrifice, and the consequences of wielding great power.

The OVA also introduces additional characters, such as Zelgadiss Graywords, a chimera warrior with a tragic past, and Amelia Wil Tesla Seyruun, a justice-seeking princess. These characters play pivotal roles in the unfolding events, adding depth to the story and expanding the "Slayers" universe. The dynamic between Lina and Gourry is further developed, highlighting their contrasting personalities and mutual reliance.

The climax of "Slayers Great" centers on a confrontation with Rezo, who has managed to decipher part of the manuscript's secrets. The battle is intense, with Lina and her allies using their combined skills and ingenuity to thwart Rezo's plans. The resolution of the conflict underscores the importance of teamwork and the dangers of unchecked ambition.

Overall, "Slayers Great" provides a compelling addition to the "Slayers" series, offering fans a deeper understanding of the characters and their motivations. The OVA maintains the blend of action, humor, and fantasy that defines the franchise, while also delving into the darker aspects of its world. The story is self-contained yet enriches the broader narrative, making it a valuable entry for both new and returning viewers.