Tbh I usually don’t like the scenes where the villain loses because half the time the villain is my favourite character and the other half the time i just don’t know/ can’t choose which is my favourite.(btw i just spent about 5 minutes designing what I should reply to your comment with manly because I couldn’t choose a scene) ( and yes that bit in brackets also took about 2 minutes)
There's often a softening of the expression, representing a humility in accepting they had lost. The villains that didn't do that were truly evil to the end.
*The moment a villain realizes they lost.* These are good moments to have in your stories, but if done incorrectly, can it make your villain not memorable, but seem lame, having a villain like Thanos, never truly lose, truly makes him all the more menacing, , ( his ending in endgame was still done correctly, 'fore he never really truly lost, they snapped him into dust, he was an unbeatable villain) Most people think that the ending of villains like Kang the conqueror defeated by gigantic ants was Lame, because he was built up to be an unbeatable villain, but only to be defeated by ants... A good example of a villain's death is the death of The goblin in Spider-Man, (seemingly an unstoppable villain) but in the end died by his own glider, (which isn't an embarrassing/lame ending for a villain, but an ending that mirrors the flaws in the character itself) - Stewart Nibroc