Zethla is a character mentioned in Fire Emblem: The Sacred Stones. He was a legendary archer from the village of Lark in Renais, and the grandfather of Neimi. He was known as "Single-Arrow Zethla," as he had amazing accuracy and could shoot any target, moving or still, with one shot. The legend states that he only carried one arrow with him when he went hunting, which Neimi later confirms. He is mentioned in some of Neimi's support conversations with Gilliam, Garcia, and Colm, mainly about how he taught her everything she knows about archery. For instance, his method for improving an archer's vision and accuracy was to stare off into the distance at far away objects. Neimi claims he once shot a snake attacking a bird's nest on a tree on a far away mountain. His skill was well known in Renais, and Garcia claims that the Renais army (and Garcia himself) tried to recruit him many times back when he was a commander. Zethla always declined, saying it was not in his nature.
In Neimi's support conversations with Colm, they recount the time Zethla actually shot at Colm (but missed on purpose), who was stealing fruit from their tree. Neimi recalls Zethla was just trying to scare him away and would never hurt him, but Colm insisted he was too fast to hit. In a later conversation, Neimi remembers that she once broke Zethla's bow, but Colm helped her fix it.
He had in his possession an archery gauntlet embroidered with a gold falcon, which he later left to Neimi as a keepsake. She ended up having to resize it because it was too big for her.