Referring to the explanations above, one of the signs of a Hajj mabroor is that someone becomes a better person than before.
Rasulullah ﷺ once told the characteristics of people who get the title of Hajj mabroor. There is a marfu’ hadith (attributed to Rasulullah ﷺ) and it has many shawahid (witnesses), even predicated as Sahihul Isnad by Al-Hakim in his Mustadrak book.