Ablation is a technique of the Iron Soul School of Martial Arts as well as The Warrior-Seers of The Burning Sodality that uses direct matter manipulation via applied willpower and discipline to physically transform portions of the body into tough ablative armor that can withstand extreme punishment and deal out the same. Similar to strengthening an item with a user's ki, Ablation instead feeds off the user's willpower and concentration.
Unlike using ki, the transformation does not have to drain energy from the body once effected, making it very potent for short spans of combat. However, natural entropic processes reverse the effect if it is not actively maintained, so most people end up having to contantly spend energy and concentration maintaining it.
Used properly, ablation can be used to make flesh stronger than steel, or "coat" a weapon in heavier, more destructiver energies. It can make a body denser, to the point where blow from a fist can be as dangerous as a strike from a sledgehammer. Used improperly, a wielder can break their own bones or tear their own muscles by not properly adjusting for the added weight and mass.