"Beyond our time, beyond our universe, there is a planet besieged by alien invaders, where a young king must rescue his love from the clutches of the Beast. Or risk the death of his world." Krull, a fantasy science-fiction flick, was released in 1983. The movie even had its own arcade game. The movie received mostly negative reviews when it was released, and it was a financial failure back in the day. Since then, it has had a bit of a resurgence due to a cult following and some positive (hindsight) reviews.
The plot for this movie was rather complicated. An alliance of nations, to be solidified by royal marriage, is formed to combat a new threat that is effecting the world of Krull. Krull has been invaded by an entity known as "The Beast" and its army of "Slayers", who interrupt the wedding ceremony, kill the kings, and capture the princess (Lyssa). Colwyn, who was to be wed to Lyssa, is the only survivor. He sets out to rescue Lyssa, but he must first find the "the glaive", and ancient and magical five-pointed weapon.
After finding the weapon and putting together a rag-tag army of convicts, Colwyn locates the Black Fortress (where the Beast lives). Along the way, many convicts are killed, but Colwyn eventually finds the Beast and Lyssa. In order to kill the Beast, the two realize they must finish the wedding ceremony, which will allow them to send a flame at the Beast which will kill it. After killing the beast, it is realized that Lyssa and Colwyn are the fulfillment of a long-believed prophecy, and everyone lives happily ever after.