She is a tall muscular woman with blond hair, shaved on the sides, with a long braid, and wears a special forces cop uniform. She first appears as a boss, looking to the defeat the protagonists, until a particular twist at the end of 7th stage happens, where she and the rest of the police forces were being deceived by the Mr. and Ms. Y’s syndicates, eventually getting the evidence to clear the protagonists’ names.
She has three phases during her boss fight: her first very early phase consists of close melee combat, then at around 90% health she requests back up from the police force much like the characters from the original Streets of Rage. These rockets will keep on firing for the remainder of the fight and shoot more frequently nearing the end; a bright red circle appears on the ground before impact and the explosions can be easily avoided by moving away or jumping right before impact. At around half health, she enters the second phase, where she now requests back up from other police officers, and she also becomes more aggressive using a jump kick to knock you back.
She appears once again in Stage 7 as a boss, changing very little in fight pattern, but now using grenades at her disposal which can be used against her by throwing them back. This time she receives back up from the Commissioner himself (2 of them in harder difficulties) from Stage 2, who still armors through light attacks when charging up his lunge grab.
- She and Commissioner are the only police bosses in the entire series.
- Estel's appearance was based on real life police officer the illustrator Ben Fiquet met once. During the summer of 2017, when Fiquet walked to his building, three police officers were trying to guess the door code. As Fiquet offered his help, he noticed their leader was a strong female officer (who would serve as the inspiration for Estel).
- Despite being a Special Forces Officer, her backups are actually Feroccio's (regular policemen) rather than Murphy's (SWAT operatives).
- She says "Backup Requested!" when calling in fire support/ backup. This term is incorrect since the correct phrase would be "Call in fire support!" and "Requesting Backup!" respectively.
- Estel's kevlar vest originally had the word "POLICE" written on it. However, this was changed to a police emblem due to issues with sprite mirroring.