Hysterical Strength

Hysterical Strength, also sometimes referred to as Superfire, is a power up technique used by some Third Generation pyrokinetics.

Overview
Hysterical strength is a technique that allows a Third Generation pyrokinetic to utilize 100% of the full potential of their Ignition Ability, whereas only 30% is usually used. This makes the users flames much stronger than usual and have a much higher temperature. When Shinra used it, his flames turned blue due to their higher heat, and they took on a more refined claw-like shape.

During Shinra's battle against Captain Burns, he was able to achieve Hysterical Strength due the overwhelming "Pressure of Death" that he felt from having to fight an actual life-or-death battle against one of the strongest combatants the Special Fire Force has ever had. While Hysterical Strength was active, Shinra was able to knock Captain Burns back from his original position with only single kick, an exceptional accomplishment considering Burns is well known for his super-human strength, and possesses an incredibly powerful Ignition Ability that enhances his physical abilities.

Benimaru Shinmon somewhat confusingly remarks that unpowered individuals can also utilize Hysterical Strength, later cryptically calling Akitaru Obi's physical might an application of "Hysterical Strength". Whether he was speaking metaphorically or literally is unclear.

Steeled For Death
"Steeled for Death" is the extreme feeling that surpasses the Pressure of Death. When one doesn't simply fear death, but accept that death is coming for them, it allows the user to unleash their full potential and use an attack stronger than anything they have ever achieved before.

This technique allows its user to commit unimaginable feats of strength, in which standard attacks will become insanely powerful. This was showcased in the final showdown between Arthur and Dragon, when a single Violet Flash completely split the Earth in two, and singlehandedly sliced Dragon in half.

Training
Training to achieve Hysterical Strength on command requires a person to be pushed to their limit, mentally, physically, and in terms of their pyrokinetic abilities. By pushing past their limit's, the high level of stress causes a person to experience a sort of death-like sensation, known as the "Pressure of Death". This results in ones survival instincts taking over and allowing one to utilize Hysterical Strength.

Benimaru Shinmon trained Shinra Kusakabe and Arthur Boyle by having them strip naked and be publicly tortured and humiliated by tying them to posts and roasting them over a fire all day and night, tying their feat to the back of a wagon and having them pulled through the streets, and hanging them upside down over water barrels with their heads below the water. Benimaru admitted that even he has never been able to figure out the exact purpose of this torture training, but he is pretty sure that there is a purpose.

After all the suffering and humiliation that they endured, Shinra and Arthur battled against Captain Shinmon for five continuous hours without rest, to the point of using up all of their oxygen and nearly getting Tephrosis. By this point, Captain Shinmon ordered them to continue anyway, as the whole point was for them to surpass their limits.

Trivia

 * This technique seems to be based on the real world phenomena of hysterical strength: a display of extreme strength by humans beyond what is believed to be normal, usually occurring when people are in life-and-death situations.
 * The aspect of Third Generations only using 30% of their full power under normal conditions may be a reference to a statement that humans only use 30% of their brain at any time.