Magma

Magma (prefix) & Magma Surge
This weapon stores the immeasurable heat of the planet's molten mantle. When this weapon is used, superheated magma occasionally surges to the surface, slowing an enemy down and inflicting massive fire damage over time.
 * 2% chance of activating, 3d20+40 fire damage for 4 tics (1 per second over 4 seconds), slows movement by 50% and attack rate by 30%, and gives a -1 penalty to attack rolls, AC, and reflex save.
 * ✅: 43-100 per tic for 172-400 total damage at a rate of 71.5 average per tic for 286 average total damage and 5.72 average per hit.

Magma Surge Guard
This item stores the immeasurable heat of the planet's molten mantle. When the wearer of this item is successfully attacked in melee, superheated magma occasionally surges to the surface, slowing an enemy down and inflicting massive fire damage over time.
 * 2% chance of activating, 3d20+40 fire damage for 4 tics (1 per second over 4 seconds), slows movement by 50% and attack rate by 30%, and gives a -1 penalty to attack rolls, AC, and reflex save.
 * ✅: 43-100 per tic for 172-400 total damage at a rate of 71.5 average per tic for 286 average total damage.