Stamina

Stamina is the bodily or mental capacity to sustain a prolonged stressful effort or activity (https://www.merriam-webster.com/dictionary/stamina), this is possessed by all characters to varying degrees.

It is difficult, if not impossible, to directly quantify Stamina into any sort of consistent or fair tiering list, therefore one must describe, in detail, the feats of stamina and endurance of a character in order to display their level of endurance.