4V's assertiveness during emergency situations
“People with the Fourth Will are peaceful and benevolent, somewhat driven by others, helpful people who first of all manifest this Will of their own very gently in everyday situations.
When a difficult situation comes - in such people, a very interesting psychological mechanism is activated, when their Fourth Will fires with all its energy, and kind of becomes like the Second Will - if this conflict is protracted, prolonged, or the First Will - if the conflict is acute or the situation is extremely complex, difficult, extreme.
This happens in the competitive activity of athletes, it happens in a situation of war (God forbid). In the Great Patriotic War, there were many heroes in Russia who sacrificed themselves - these are people with the Fourth Will who became heroes.”
She also often mentions this trait in her descriptions of 4V types. Example from the Berthier's description:
"In a difficult or extreme situation, he acts decisively and is able to surprise with the adequacy of actions, will, heroism, courage, physical and mental endurance, intellectual power. In sports activities, he is able to achieve records and win."
I don’t have enough experience with 4Vs irl, but I can see this pattern in fictional 4Vs. I don’t remember Beastars that much, but I think Legoshi can serve as a good example - kind of insecure, nice and submissive in daily life, but later he became pretty driven and was able to act very assertively for Haru’s sake.
This info is from Afanasyev’s wife and I don’t remember it being in SoL, so I thought it’s worth dropping it here. Source.