I can confirm this works, because this how I finally nobbled that sumnabitch last night. I died about fifteen times before I did, half the time to him, and half the time to the knights. The latter are trivial at this stage… unless you’re underestimating them and rushing because you’re sick of the fucking walk and think you’re a big shot, like me. I actually got to Allant first time, and was surprised to see my bloodstain on the floor - it’s been two months since I played, so I’d forgotten where it was. Anywho, in the fight, I grabbed it and discovered it had 140k souls in it. Schwing! He then killed me with about 20% of his health left. No problem, I think… and then fail to stagger one of the Fat Ministers on the bridge and get one-shot on the way back. Ouch.
I digress. As I was saying, cheaping him with the bow definitely works. I used a compound viscous longbow +4. I was using Cling Ring and Regenerator Ring, and wearing Dark Silver armour, so thief ring and armour don’t seem to make a difference as to whether he detects you. Step-by-step breakdown:
Press X to move through the fog from the lift. Don’t move again. At all.
Equip your bow, go into aim mode. You should see Allant’s head in the distance. It will be tiny. Aim to the left of it - arrows pull to the right of your crosshair in flight over long distances. It might take you a couple of arrows to find your range, but don’t worry, he isn’t going anywhere. Did I mention don’t move? When one lands, keep shooting. He moves steadily backwards, to the point where you won’t see him at all, but you should still be arcing the arrows over the steps in the same spot and hitting him. I was doing 50 damage at the start and 25 by the end. I had 100 arrows on me and that reduced him to about one-third health, so I would recommend bringing at least 200.
So yeah, I ran out of arrows. Swearing ensued. I buffed up with Total Protection, Purple Flame Shield and LSoM, then went in to finish it like a man. Having 98 Full Moon Grass from running the level so much helped. Total Protection was a complete lifesaver. I maintained that, dodged a bit, and hacked him up. There was still no margin for error, but it was a lot easier to not make errors when the length of the fight is significantly reduced. I did a little victory fist pump, grabbed the archstone… and, glowing in triumph, promptly ran straight down the newly-arrived fucking great hole in the middle of the Nexus and died. If that isn’t Demon’s Souls in a nutshell, what is? Anyway, new game + awaits!