I was thinking, since I have a long, enclosed bridge that is surrounded by lava on the outside. I would put a lava source at two points, so when triggered they pour down infront and behind the trigger location (Trapping the person who triggered the lava), then the trap doors slowly open up from the edges and pour lava in, into the trapped person is covered with lava~
btw: If we ever get a server, I'm making a masterpiece maze of death =3