"Hellfire" redirects here. For the yoyo obtained by defeating enemies close to the underworld, see Hel-Fire.
The Magma Stone is an accessory that drops from Lava Bats (2% chance) and Hellbats (0.67% chance) in The Underworld. It causes the wearer's melee attacks to inflict the Hellfire / On Fire!debuff on enemies, and also add orange flame particles effect on both the weapon sprite and their projectile that gives off light. The duration of the debuff is random, and varies according to the table on the right.
The Hellfire debuff is a stronger version of On Fire! and causes the afflicted enemy to lose 15 instead of 4 health per second.