In *Kingdom Come: Deliverance 2*, the "Canker" side quest becomes available early in the game, and you'll need to have completed "The Jaunt" beforehand. This quest is a great opportunity to acquire a mace or some extra Groschen. Here's a step-by-step guide on how to successfully complete "Canker."
To initiate the "Canker" side quest, you'll need to have a conversation with Gules at Semine. You can easily pick up this quest during Lord Semine and Agnes's wedding by talking to Gules while he's enjoying a drink. Alternatively, you can start the quest before the wedding by visiting Semine and speaking with Gules during his patrol. Inquire about his past with a band of bandits and express your willingness to help him eliminate the remaining members. Canker, one of these former bandits, will be your first target.
Upon accepting the quest, Canker's location will be marked on your map, north of Nebakov Mill. Be cautious, as the path leading to him is often patrolled by bandits who may attempt to ambush you. You can choose to sneak past them, engage in combat, or simply flee. While these random bandits aren't particularly challenging, it's frustrating to lose health before facing Canker and his group.
Canker's camp is nestled in the mountains, and it's easy to overlook as you need to navigate through a narrow gap to reach it, similar to the approach to the Hermit's house in the "Wedding Crashers" quest. Before entering, ensure you're prepared for battle, as you'll encounter several bandits alongside Canker.
Depending on the order in which you take them down, some bandits might flee. However, you must eliminate most of them, so don't assume you can avoid fighting every bandit there. Fortunately, Canker won't escape, allowing you to complete the quest by killing him.
After defeating Canker and his bandits, loot Canker's body to prove you've fulfilled your agreement. Make sure to take the Light Mace from him, though you're welcome to take any other items he's carrying. Once you've collected the necessary proof, return to Gules to complete the quest.
After completing "Canker" in *Kingdom Come: Deliverance 2*, you'll need to wait a full in-game day before you can pick up the next quest involving Gules' former bandit allies. Once the day has passed, speak with Gules to start "Handsome Charlie."