Should I Kill Gatekeeper Gostoc?

When It Makes Sense

• Good fit: You find the rune drain in Stormveil Castle frustrating and want it to stop immediately. Killing Gostoc prevents him from taking a portion of your dropped runes whenever you die inside the castle.
• Good fit: You are on a second or later playthrough and already know you do not need his late-game rewards, or you simply want the convenience of purchasing his stock through a Bell Bearing at the Roundtable Hold.

When You Should Avoid It

• Warning sign: You are a completionist on your first playthrough. Gostoc has a linked questline that ultimately expands his shop and lets you obtain an Ancient Dragon Smithing Stone, which is one of the most valuable weapon-upgrade materials in the game.
• Warning sign: You want to experience all NPC interactions and lore tied to Stormveil Castle, Kenneth Haight, and Nepheli Loux. Killing Gostoc early removes those story beats from your current playthrough.

Pros and Cons

Pros

• No more rune theft: Once Gostoc is dead, he can no longer siphon a portion of the runes you drop when dying in Stormveil Castle, which adds up quickly if you are struggling with the area.
• Immediate shop access: He drops his Bell Bearing, allowing you to buy his inventory from the Twin Maiden Husks at Roundtable Hold instead of tracking him down later.

Cons

• Lost quest rewards: Killing him before completing his questline locks you out of the expanded shop and the Ancient Dragon Smithing Stone he eventually sells.
• Missed content: You lose related NPC dialogue, world-building, and a satisfying resolution to a small but memorable side story in Limgrave.

Decision Checklist

• Have I already progressed Gostoc’s questline far enough to buy the Ancient Dragon Smithing Stone from him?
• Am I losing enough runes in Stormveil Castle that the theft is genuinely hurting my progress?
• Is this a first playthrough where I want to see as much content as possible, or a speed or challenge run where efficiency matters more?

Alternatives to Consider

The most balanced path for many players is to leave Gostoc alive until his questline is complete and you have bought the Ancient Dragon Smithing Stone, then kill him afterward if you still want to stop the rune drain. Alternatively, you can minimize losses by leveling up or buying items before entering dangerous castle sections, or by moving through Stormveil quickly so Gostoc has fewer chances to steal. If you are playing offline or simply do not care about achievements, killing him early is a low-stakes convenience choice.

Final Recommendation

For first-time players, the best default is to keep Gatekeeper Gostoc alive and finish his questline so you do not miss the Ancient Dragon Smithing Stone and related story content. For repeat playthroughs, or if the rune drain is making the castle feel unfair, killing him early is a reasonable quality-of-life choice. If you want both benefits, complete his quest and buy his final item before striking him down. Because this is a single-playthrough decision in a video game, choose the path that best matches your current goals and be aware that you can make a different choice in a future New Game Plus cycle.