Causes fire damage and decreases opponents’ fire resistance within a certain radius. Allied players receive a bonus to ice resistance. If the combat art Icy Evanescence is active within range, the spell with the higher level will cancel the weaker one.
A player may gather as large a mob as possible, casting Fiery Ember while being attacked. If done successfully, each monster will be damaged by several of the damage points/volcanoes, resulting in significantly increased damage, as well as effecting a chance to set monsters on fire with Chance for Burn, etc.
Due to its reduction to enemy fire resists, it's useful to cast Fiery Ember before attacking with CA's like Furious Emblazer or fire-damage weapons socketed with lava chunks.
Fiery Ember has a wide radius that can be increased even further with +combat art range item modifiers, killing everything on the screen.
Pros and Cons
Can be useful against very large mobs that are not moving, for example enemies within melee range
The effect follows the Temple Guardian around while it lasts
Fire resist reduction can be useful when paired up with a fire High Elf
Damage mitigation protects against ice spells and melee attacks
Temple Guardian's CAs Fiery Ember and Icy Evanescence increase target's vulnerability to Ice or Fire; High Elf's Buff Crystal Skin has "Feel Cold" modification that causes all targets in close vicinity to the caster to be more vulnerable to Ice Damage. These CAs cause all enemies in Area of Effect to have modifier "Damage Vulnerability Ice/Fire +x%" which not only removes these enemies' resistance to Damage but can decrease it below zero, causing CAs to deal more damage than the value stated in CA description. These CAs do not affect target's Armor, but decrease "Damage Mitigation" modifier by fixed percentage (not by percent of target's mitigation like Ancient Magic).