Master Tyranna is a Selkath. She is a Jedi Master who has devoted herself to teaching. Having been born during the New Sith Wars her teaching has taken the route of teaching between combats and even during combat. Since emotions can lead to the Dark Side her lessons during combat tend to lean towards calming her students.
[I didn’t want this backstory to be as inclusive as other backstories because she will be the Jedi Master the players are studying under.]