The heretic is always better dead...
The Nuke Match
Basically, the match is set up so the apron is surrounded by barbed wire so nobody can escape and the ring apron is layered with a liquid even more explosive then petrol. Above the ring is a container, which is flameproof, and inside is a button. The button can only be pressed once one, and only one, competetor is inside the container, and the other person is outside. Then, when the button is pressed, the whole ring and surrounding area goes BANG!!
... No, I'm not crazy... I just like things that go bang... ninja
Between 2-8 players.
... And mortal eyes cannot distinguish the saint from the heretic.