Ember Spirit's Activate Fire Remnant spell is available for cast all the time, even when having no Fire Remnants up. This is basically pointless. The spell should be inactive while no Fire Remnants of the caster are on the map.

Compare it to Puck's Illusory Orb. The Ethereal Jaunt sub-spell is inactive, and is only usable while an Illusory Orb is flying. Activate Fire Remnant should do the same. Be inactive normally and turn active while having Remnants placed.