Indomitable Will

Indomitable Will is the ability belong to characters that possess exceptionally strong willpower compared to the others.

Overview
The user has unnaturally strong willpower, enabling them to endure great physical pain and keep fighting for a long period of time despite suffering severe injuries or running out of stamina, which would normally result in incapacitation. Indomitable Will makes the user refuse to surrender no matter how much physical and mental damage they may have taken and possibly even allows the user to surpass their limitations, becoming even stronger.

Trivia

 * It is possible that Saitama's willpower is the key factor in attaining his incredible level of strength and he has also shown to remove his limiter.