Jencks is the a "Ranger" who uses a bow and arrows for battle.
Jencks' past is not very deep. all we know is that his family dies in a village raid, and he was taken by the knight raiders. Some Rangers shot the knights down and took him to a ranging camp, where he spent most of his childhood at. When he was about 15 years old he left the ranger camp and went on his own adventure. On the way he found a broken bow and brought it along to find someone who could repair it. he found an old woman, claiming she was a witch or magician. She fixed the bow, and put a spell on it. Jencks named his bow "Hawk Strike"
Jencks' first appearance is in the woods near Nibelheim watching the group progress. He saves Korgen from Kelco once in the woods and sends a letter with his bow. When Fravir sees him, Jencks states he is one of the Greenhood Rangers. Jencks made an error, hitting Linda with a stunning arrow making Rhade angry. Jencks manages to escape Rhade though.
Within Chapter Three, Jencks joins the group and helps Brendan and Ether obtain one of the three spirit shards. Shooting a mighty arrow of pure light from his bow, he hits straight through the Guardian, The key and Ether. letting Fravir, Saratonia and Brendan enter Ether's heart.