Cath is a playable character in Fire Emblem: The Binding Blade. She can be spoken to three times with Roy across the several chapters she appears in. Her village was burned down by her father by the order of some nobles, so she hates nobles with a deep passion, and steals from them as a result. She regarded Roy as a snobby noble at first and did not believe his sympathies when she told him her tale. After hearing that he would help her rebuild her village, she joined Roy wanting to see the proof of his claim.
Roy must speak to Cath three times for her to be recruited, however she shows up in more than three chapters. She first appears in chapter six, then eight, twelve (this is the earliest she can be recruited), sixteen, twenty (eitherversion), and as late as twenty-two.