If you’re desperately seeking out the one battle in Bloodborne that could be considered easy, the Celestial Emissary is definitely going to be the closest you’re going to get. Don’t get me wrong, nothing in From Software’s latest title is simple, in the traditional sense of the word, but this morphing blue boss doesn’t punish players as much as say Father Gascoigne or Vicar Amelia do. There’s no need to feel bad if you’re struggling with this unique battle inside the Upper Cathedral Ward’s Lumenflower Gardens, as Bloodborne seems to have a challenge for everyone. Still, this isn’t the most difficult battle to understand, so this guide will be relatively rudimentary in the grand scheme of things.
In order to get to this battle, you’re going to want to obtain the Orphanage Key from one of the head-sucking enemies on the second floor of the Upper Cathedral Ward’s Great Hall. Be sure to try and take out the enemies in this section one at a time, as there’s a fair chance that you could be overwhelmed or trapped in a corner if you get too aggressive. Once you get the Orphanage Key, head down to the main floor of the Great Hall (the area in which you fought the four blue-eyed lycanthropes), and unlock the large door at the back of the room. The path to the Lumenflower Gardens is fairly linear, and it might be in your best interest to sprint through as quickly as possible to ensure you don’t have to waste any of your Blood Vials. Upon entering the Gardens, you’ll be greeted by a Celestial Mob, which coincidentally houses the Celestial Emissary.
In order to isolate the boss and officially begin the battle, either use a large area-of-effect weapon (i.e. the two handed axe) or a standard quick weapon to clear out every member of the Celestial Mob. Eventually, one of the enemies will cease to die, and the traditional yellow boss health bar will appear at the bottom of the screen. Try and unleash as many attacks on this enemy before the Mob spawns again, as you’ll be able to get a ton of damage in while remaining fairly safe. Once the Celestial Emissary’s health reaches the 50% mark, it’ll transform into a much larger version of itself and the Mob will respawn.
During this second battle segment, there are two things you have to worry about. The first is avoiding the Emissary’s massive side-swiping attacks, which can be dashed away from relatively simply. Second, and perhaps most important, you need to avoid getting trapped and/or overwhelmed by the smaller Celestial enemies. In order to get as many attacks in as possible, there are three basic strategies you can use. The simplest technique would be to poison the Celestial Emissary with Poison Knives and run to the top level of the Lumenflower Gardens to concentrate on the smaller foes. Granted, you’re going to need a handful of Poison Knives to accomplish this, but if you’re willing to part with these awesome pieces of equipment, this fight will be extraordinarily simple. The second strategy involves simply diving in headfirst and attacking the Emissary with no regard for the Mob. If you have high Vitality and Strength statistics, this will end the battle quite quickly. Finally, the safes strategy would be to lure the Mob upstairs, killing them all, and heading back downstairs to do damage to the Emissary before repeating the process.
Eventually, your attacks will overwhelm the Celestial Emissary, granting you a bunch of Blood Echoes, a high-level Communion Rune (and likely a trophy), some tasty Blood Gems, and easy access to the next boss fight.