Which 1980s-90s action/thriller movie am I looking for?

It’s been driving me crazy the last week looking for a movie I saw when I was a little kid. The only major parts I remember are:

-The protagonist discovers the antagonist’s alias name in a cryptic note where the first letters of each line spells the name downward instead of across. This causes a flashback of him fighting the antagonist until he snaps a harness, presumably causing the antagonist to fall to his death. -Later in the movie, the antagonist has a man in a cage suspended over water in an underground cavern or catacombs. -The twist is that the antagonist was masquerading as a wheelchair bound friend with glasses and a pony tail. He stands out of the wheelchair and gets scratched by the woman he befriended, but the skin under her nails is fake. He then peels the fake skin off his face revealing some scarring and takes out his pony tail before laughing maniacally and the woman screams. The scene then cuts to the antagonist taunting the protagonist on a voice recorder. -The protagonist and woman reunite in the underground cavern/catacombs. She asks who the antagonist is. The protagonists says, “His name is________. He calls himself______”