A few tips for defeating Death.
1) Make sure you are a ranged vocation as I found melee to be pretty ineffective against Death. 2) Make sure your pawns are ranged offensive vocations. (You don’t need any healing for this fight. If you get hit your dead.) 3) To make the fight easier bring lots of magic boosting curatives (if you or your pawns are a magic vocation), blast arrows (if you are a bow and arrow based vocation), any curatives to snap you or your pawns awake if you get put to sleep, and maybe some liquid vim.
The strategy I used to beat him was to keep moving in a constant circle kiting Death around. The only time you should stop moving is when he is casting his lantern spell while making sure you are out of range of its effects. You almost NEVER should double back on him, meaning do not switch directions your moving or he will likely use his scythe and 1 shot you or your pawns. The only time switching directions seems to work is if he vanishes and reappears in front of you, then you should run the other way. If he manages to sleep any of your pawns, the best chance they have on not getting one shot by his scythe is for you to run far enough away so that Death will vanish and reappear closer to you, but away from your sleeping pawns. Other than that he isn’t really that hard. He just has a crap load of HP so it’s a tedious fight, but fairly simple.
I hope this helps! Good luck!