The magical ring
This is often included and fought over but it is much rarer for it to be used as a weapon.
Whether gauntlets, wands, angel statues or worm holes etc, time can be used as a weapon by transferring someone back or forward in time, transplanting them in a variety of situations or just out of the game so that they are effectively defeated.
These can be forced to fit a situation, thereby causing someone harm or death.
The transporter or teleporter
Someone can be annihilated by either sending them to a dangerous place or by disintegrating them but not re-materialising them.
Portals or wormholes
Can be used to chop or crush an enemy.
The cloak of invisibility or invisibility technology
This can be used to convince people to enter dangerous situations, especially if they were promoted as not just invisibility cloaks, or to hide them from those who would avoid killing them if they could see them.
Whether truth is revealed due to drugs or magical spells, the truth can cause death just as often as it can save lives.