The Minion

The Minion also known as Fallen Knight in Canada, is a 1998 American and Canadian action supernatural horror film directed by JeanMarc Pich and starring Dolph Lundgren and Franoise Robertson.

The Minion arrives at the Templars headquarters just before Lukas and Karen do, taking the Templars by surprise and killing most of them. Bernhard, one of the Templar Knights, manages to kill the Minion, but in his eagerness to prove himself better than Lukas, he accidentally allows the Minion to take possession of him and thus insert the key into the gate. Lukas and Karen arrive shortly after, and while Karen tries to remove the key from the lock, Lukas battles the possessed Bernhard and kills him. Together, he and Karen, although tempted by the Antichrist himself, manage to prevent the gates unlocking just before the final seal on the door is burst. With the Templars decimated, Lukas decides to rebuild the order, and Karen spontaneously declares to join him in his efforts, marking the dawn of a new generation of Templars to guard the gate and the key.

Source: Wikipedia