FlameStreak

FlameStreak was a young warrior of FearClan and Mentor.

as you read in "River's Mistake" on Wattpad BadgerStar mentioned that he was younger than most Mentors,

so he couldn't have been a warrior for too long.

Apprentice:

FlameStreak's Apprentice was Amberpaw, who goes by the name River now.

River seemed to be very close to her mentor, and so was FlameStreak to his Apprentice.

during River's early life of Survivorpack she has visions of FlameStreak, telling her "River will save the pack" and that

war between the clan, Fierce dogs, and the pack was coming.