Draining opponent's health
Set a magnet wall trap then set a Blast Bomb directly in front of the magnet wall. Stand behind your trap and wait for your opponent to walk into it. Activate the magnet wall trap first. When your opponent is stuck to the wall, activate the Blast Bomb. It will drain half of their health and they will catch on fire causing additional damage. Note: This also works with the Iron Ball and the Flare Rock.
Easy 5-hit combo in the Torture Room
Set up a spring board facing the crucifix (spiked wheel on the wall). The spring board should be one square away from the crucifix. Put the pendulum in between the springboard and the crucifix facing the wall, so that it pushes them into the wall. Place the saw blade on the wall pointing toward the electric chairs. Once set up, here is how it works. Lure them to the spring board and set it off using X. They will hit the crucifix and become stuck for a moment. Press Triangle to launch the pendulum. After the pendulum hits, use the sawblade to push the crucifix down the stairs and into the electric chair. This creates a 5-hit combo that should kill most enemies in one pass without having to repeat the process.
Special kill
In the room with the obelisk you will notice that there is a stained glass window. You can break it if the obelisk falls on anyone who walks underneath it set up a spring floor board 2 spaces away from the obelisk splatter and then run over to the yellow diamond in the corner by the door. DO NOT TOUCH IT YET spring the floor when the person is near it and send them under the obelisk while the obelisk is still down rum through the yellow diamond an iron peg should be released if the peg is shot at the right time it will hit the window and shatter the glass....the glass will impale anyone near it....instant kill.