Bullet That Can Kill the Past Guide

The 過去を始末する弾 is a passive item assembled from four components spread across four floors of Enter the Gungeon. Once built by the 鍛冶屋 in the 鍛冶場, it allows any Gungeoneer to enter and confront their past. It can be obtained from the 鍛冶屋 an unlimited number of times after it has been built once.

The sections below follow the order how to forge it → where each of the four pieces is → how to use it → things to watch out for. The four pieces are independent and progress is permanent, so there is no need to gather them all in a single run.

How to build the Bullet

Collect all four components across separate floors and bring each one to the 鍛冶屋 in the 鍛冶場. The components do not need to be delivered in a single run — each one you hand in is remembered permanently.

Components

プライムプライマー

プライムプライマー — Found in メインガンジョン. Purchase it for 110 ケーシング from 店主 – ベロ's shop.

• Discount items do not reduce its price.
• It is locked in a glass display case and cannot be stolen with the フックガン.

アルカナガンパウダー

アルカナガンパウダー — Found in ブラックパウダー採掘場. A large empty-looking room contains invisible minecart rails over a chasm. Ride the minecarts and dodge-roll between them to cross.

• The アルカナガンパウダー is the only active item among the four components — consider using the パイロット (character differences: see All Characters Guide: Starting Loadouts & Traits), who carries an extra active slot, when transporting it to the 鍛冶場.
• If you have a flight item such as ロウで固めた羽, you can simply fly over the chasm.
• You can slow down a minecart and stop it beside the next one to make jumping across easier.
• Falling into a pit in this room resets the entire room, deleting any dropped items.

超次元の鉛

超次元の鉛 — Found in Hollow. A room with a chasm hides an invisible path to the item.

• Shoot and reload to drop shells — they land on invisible solid ground and mark safe tiles. Starting guns work especially well since they eject shells backwards.
• Guns that leave liquid or debris on the ground, such as 化石ガン or メガウォーターガン, will reveal the path.
• With 大穴王の首かざり, trial and error is a viable method since there is no penalty for falling off the path.
• Any flight item (ロウで固めた羽, ジェットパック, バルーンガン, ゴーストリング, ネコキングブレットの玉座) lets you cross the chasm without needing the path at all.
• The フックガン or 十字キー can be used to cross the chasm or snag the item itself.
• 血染めのスカーフ can also cross the chasm — hold down roll while standing at the very edge of the ledge to charge a blink to the other side.
• If you fall off the path, it will be randomly regenerated.

黒よう石の薬きょう

黒よう石の薬きょう — Defeat the ドラガン, then destroy its skull to reveal the casing.

• This is the only component that cannot be stolen by the かしこいネズミ.
• It can also be re-acquired after giving it to the 鍛冶屋, making it the only component obtainable more than once.

Using the Bullet

Once you have the 過去を始末する弾 in your inventory, the Gun That Can Kill The Past appears at the end of a floor. Shooting yourself with it lets you enter your Gungeoneer's past. The Bullet cannot be dropped.

You must have the Bullet before entering the 時空の狭間 — it is not possible to retrieve it once you cross that threshold.

Notes

• Carrying the Bullet is not required to access Bullet Hell or fight the ゾンビキング.
• The かしこいネズミ can steal the Bullet. With かしこいネズミの指輪, it can be traded for an S-tier passive item.
• Using the Gun That Can Kill The Past without the Bullet will still let you shoot yourself and reach the credits screen — but the run ends there instead of entering your past.
• Having クローン when you die and possess the Bullet has no additional effect.
• All rooms guaranteed to spawn because of a component will no longer appear after that component has been turned in.
• スパイス can replace the プライムプライマー in the shop if enough スパイス has been used.
• If your co-op partner dies during the ドラガン fight, they lose the Bullet upon revival — but they can still fire the Gun That Can Kill The Past at themselves to enter the past.