In Boo to You she told the Rescue Riders about a ghost called Phanthomfang, but later, they discovered that there is really a ghost. Leyla discovered that it has a scale and it turned out to be a Slinkwing dragon named Lurke. Later, he got defeated.
In Treasure Riders, she also appeared. Waldondo del Mundo told Marena about Odin's Gem and where to get it. They followed the map along with the Rescue Riders, except Burple. They followed the map and passed the booby traps. In the ship, there is a treasure in a room, but Waldondo locked the room with Rescue Riders inside. Later Marena is riding on Burple and she stopped Waldondo and freed the Rescue Riders.
In Hunt for the Golden Dragon, Waldondo is back and told the Rescue Riders about the map to the Golden Egg of the Golden Dragon. Once the Rescue Riders reached the place of the Golden Dragon, Waldondo and the other pirates know where the Golden Egg is, since they followed the Rescue Riders. Marena, who is in disguide as Waldondo's henchman stopped him.
Marena appeared as a slim elder woman with grey hair. She also had an eyepatch. Her clothes are dominantly in different shades of purple and she also had shoulder guards.
Marena is a wise type, since she knows about the Dragon Dreaded Flu and she knows that the help kelp is the cure. She is also a sneaky type who comes out unexpected, since she did that to Waldondo, because she knows he is a traitor. Marena is also an adventurous type.