Full Power Consumption or Total Power Consumption is when an Awesome power is too great or powerful for the lame poser attempting to wield it. This can be the overcharging (to the point of self-destruction) of their innate superpower, or due to the proximity of some other power-augmenting person or relic, or because some malicious entity or even the sentient power source itself is attempting to overtake a frail mortal form, destroying it in the process.
This is often, but not always, preceded by Power Madness. Those are the lucky ones, for they realize only in their final seconds what is happening, usually too distracted by maniacal cackling. Either way, it is quite a disturbing and painful way to goo.
A common occurrence is for a hero going into meltdown to be coaxed back from the brink using Heroic Willpower, or forced to do a Heroic Sacrifice and fly away to save those nearby. If a Love Interest is nearby, a Cooldown Hug can reliably stop the meltdown. Occasionally, a hero or villain might purposefully trigger it to try and kill their rival, since the Sphere of Destruction such a meltdown generates tends to be pretty devastating.