Note: This boss guide contains significant end-game spoilers for Bloodborne. If you don’t want to know what the final sequences entail, navigate away immediately.
Before we dive into exactly what you have to do to defeat Gehran, The First Hunter in Bloodborne, it would help to understand exactly what you have to do in order to actually initiate this fight. After going through the Nightmare of Mensis, defeating Mergo’s Wet Nurse, and returning to the now-burning Hunter’s Dream, you’ll learn that Gehrman has relocated to the flower-filled field behind the workshop. Before going through the once-closed gate at the bottom of the main hill, be sure to stock up on Blood Vials, Quicksilver Bullets, and whatever status items you like to use in battle (such as Fire Paper). When you feel as though everything is in order, head over to the base of the massive tree in this new area and speak to Gehrman. He’ll present you with an interesting choice, both of which lead to alternate endings. Being that you’re reading this guide, I’ll assume that you chose to refuse Gehrman’s offer of a quick death. Once you chose “Refuse,” a cutscene will initiate, Gehrman will reveal himself as The First Hunter by rising out of the wheelchair you’ve seen him in for the entire campaign.
The battle against Gehrman involves a number of different enemy strategies, all of which can kill you extremely quickly if you’re not careful. It goes without saying that you should spam Blood Vials whenever possible, as it’s very simple to find yourself dead if you have under 50% health. For the first half of the fight, Gehrman will use a two-handed scythe and some standard Hunter abilities (namely a gun and a shorter version of his Trick Weapon), not unlike Father Gascoigne during the second stage of his battle. As you know by now, these two-handed swings are relatively simple to counter with your firearm. Whenever Gehrman winds up to swing sideways in your direction, fire a Quicksilver Bullet into him and initiate a Visceral Attack. It’s definitely possible to beat Gehrman without pulling off a single Visceral Attack, but these high-power moves are going to make things a lot more manageable. Make sure to stay locked onto him for as long as possible, as side-stepping his attacks is the key to victory (the Old Hunter Bone is extremely valuable here).
After you do enough damage, Gehrman will pop his scythe back into its one-handed orientation and whip out his gun. It’s best to stay close to him during this segment of the fight, as too much distance will lead him to start firing his gun, thus opening you up to be Viscerally Attacked. Once against, you’re going to want to dash around him as much as possible, all while getting one or two quick attacks in whenever possible (I found that the Saw Cleaver was extremely useful here). Things start to change once Gehrman has under 50% of his health remaining, as he’ll become a much faster, white-flame-engulfed version of himself. Those who have become accustomed to using the Old Hunter Bone will recognize his dash-warps, being that they’re identical to the effect using said item grants Hunters. It’s definitely possible to attack him during this transformation, but try not to get too reckless, as you might find yourself caught inside of a flurry of strikes. He’ll generally
attack you in waves of three swings, so once he attempts to hit you the third time, dash in and get as many attacks in as possible. There is a way to avoid having him transform via the use of an attack-dash loop that locks him into a specific move set, but unless you do this perfectly, he’ll wind up transforming anyways.
If you’ve been playing conservatively, ensuring that your dodges set up a couple of well timed attacks every few seconds or so, this battle will quickly turn in your favor. If you’ve been dying a lot, the good news is that you’ll simply respawn in the Hunter’s Dream over and over again, so you’ll have ample opportunities to adjust your strategy. The one thing to keep in mind is to use your dodge far more than you use your melee attack; do this and victory (and one of the endings, though not the true version) will soon be yours.