One of the most badass weapons in Bloodborne, the Flamesprayer, is available at the early stages of the games, but is easily missed if you are not vigilant in your quest to interact with NPCs. As its name implies, the Flamesprayer is essentially just the Bloodborne version of a flamethrower.
In other words, once you unlock it, instead of shooting individual quicksilver bullets when you press L2, you instead exchange those bullets for the ability to incinerate your enemies with a constant stream of fire. Each bullet buys you about a second or two of flames, giving you at least a full half minute of flaming fury if this weapon happens to trigger the little pyromaniac inside of you, unable to resist.
This may be one of the most simple weapons to obtain for free within Bloodborne other than your starting weapon. The hardest part about unlocking this weapon for yourself is that in order to do so, you needed to have surpassed the second boss battle. Once Father Gascoigne has been laid to rest, you can either run back to the Central Yarnham lamp or you can return to the Hunter’s Dream and then teleport to the Central Yarnham lamp. This one:
If you were really paying attention the first time you walked through this area, you may have heard a man coughing when you first activated the Central Yarnham lamp. If you didn’t notice then don’t feel bad. It took me an infinite amount of passes by to accidentally stumble upon the sick fellow who resides behind that caged window.
However, if you are more vigilant with your eyes than with your ears (and still more vigilant than I), you may have noticed something else. Just to the left of the blue/white Central Yarnham Lamp secured into the ground is a red/orange lamp protruding from the wall. As you progress throughout the game, you will notice more of these red lamps. Eventually, if you are connecting the dots, it should not take too long before it occurs to you that every single time you see a red lamp, there is a nearby NPC with which you can interact, often either behind a door or a window.
Once you have slaughtered Father Gascoigne, return to this coughing man behind the caged window. He’s kind and his name is Gilbert. Go through all of his dialogues. While he acknowledges that he himself is in no condition to carry on the good fight, he is more than happy to bless you with his Flamesprayer. Enjoy!
Note: First posted by Ian Lepkowsky on Twinfinite.net