Final answer:
Scar is the character who warns someone not to get self-righteous and points out that they only have themselves to blame.
Step-by-step explanation:
The character who warns someone not to get self-righteous and mentions they only have themselves to blame is Scar. This conversation occurs in the animated film "The Lion King," where Scar chastises another character for their self-righteousness and suggests they look at their own actions as the source of their problems. This is reflective of Scar's manipulative and conniving nature, often shifting the blame to others rather than acknowledging his own faults.