Definitely not a one-shot boss, Laurence, the First Vicar, is fairly challenging - not Ludwig levels, mind you, but definitely not easy. This might be the only boss in which I've literally run out of Blood Vials fighting him, making that victory all the more pulse-pounding.
You fight Laurence by acquiring his human skull (it's a Nightmare, go with the logic) in the hidden area below the Surgery Altar elevator. You then just return to the nightmare version of the Grand Cathedral and now he'll wake up and fight you.
Phase one is literally a fire-buffed version of the Cleric Beast (trust me,) where his swipes and such are granted some additional splash damage thanks to his fiery nature. He gets a few new attacks around 70% - I recommend being conservative and dodging backward to heal when you need to.
At 40 or 30%, the bottom half of his body falls away and he begins to leak lava everywhere - this stuff does not persist forever, but you'll want to watch your step regardless. He will frequently do a very nasty crawl/slash attack that goes on for quite a while. I found that dodging to his right (your left) tended to allow you to get in some hits without getting hit (too hard at least,) but you want to be both careful and also aggressive, as he'll keep doing this, moving pretty fast.
He rewards yet another Oath rune, this one turning you into a beast, which I assume works well with Beast Blood Pellets and weapons/items that work with Beasthood.
Having downed another boss (I think I have only Maria and the Orphan of Kos left in the DLC, and then Ebrietas, Mergo's Wet Nurse, Gehrman, and the Moon Presence in the main game,) I decided it was time to start my new character.
Alice Canwick is a Professional, and she'll be focusing on Skill (and possibly Bloodtinge - since Rackham is Strength and a bit of Arcane.)
Obviously, playing for a few weeks and being a bit more familiar with the area made my trip through Central Yharnam way easier this time. The only time I died was because I didn't realize the Yharnamite at the beginning could climb the ladder to the Central Yharnam lamp, so I was talking with Gilbert when all of a sudden I started getting slashed to death.
One very interesting thing I realized is that you can find at least two Madman's Knowledge before fighting the Cleric Beast or Gascoigne, so I was able to return to the Dream and level up. I also managed to upgrade the Threaded Cane twice before duking it out with the Cleric Beast.
So far I'm wearing the Hunter set (I see the Yharnam Hunter set is available in the Messenger shop - I had forgotten that was where I got it) and I've got the Hunter's Pistol, a +2 Threaded Cane, a Saw Spear and a Torch.
The Cleric Beast went down quite easily - there was maybe one moment where my health dropped to dangerous levels - and I've talked to Eileen as well as Gascoigne's daughter. Man, I wonder if there's any way for her not to die. Probably not.
At some point I do think I should make a true Arcane-focused character as well. I guess lots of Elemental gems? Honestly I'm not entirely sure how Arcane builds work. Also there's Bloodtinge, but I think that basically just works with the Chikage.
Anyway, I think I'll probably still focus on getting everything down on Rackham. I want to get every item I can and upgrade as many weapons as possible before starting New Game+. Lady Maria is definitely a challenge, but I have gotten her below 50%, so I think this is probably going to be more Laurence-level challenge than Ludwig.