VIT is good to level, but I think I wrongly emphasized END ahead of STR. I watched some other people's blind playthroughs and they did more damage despite being similar level to what I was, but they all had their STR or SKL . So my next few levels will be dedicated to STR, so that maybe I can get Rom down fast before my luck runs out with avoiding his meteor showers
My guide to builds (I have 7 lvl 150 characters). All builds pretty much come online in new game +, as the weapon options are late. Simple stuff overall but I'll go over it for fun.
You mainly want to focus on two attack stats - STR/SKL, STR/ARC, STR/BLO, SKL/BLO, and increase them to 40. Skill affects critical damage and so is generally more convenient, but the big STR weapons have a tactical advantage in some parts.
Note that SKL/ARC is an obtuse option. STR/BLO is also fairly niche, it really is a Bloodletter build (dlc weapon) ; they also can use canons which are now shit (but still cool).
There is the added option of going only one stat, pure ARC, which is powerful and has a lot of possible variety ; it can go up to 99 as it scales with hunter tools (which are not great but are an option that will trivialise some parts especially in new game). However beware because it will give you extreme trouble clearing the Orphan of Kos (he takes no shit from ARC damage). This is a problem because he is by far (at least to me) the hardest boss in the game bar dungeon bosses. ARC gives you the option of going broccoli though, which is great.
A fun option for the quality build (STR/SKL) is going beast, too.
For END you really just need 15 for the entire base game. There is no big stamina issue in this game, since there's no armor. Later on you can increase to 25-30 if only because you have the points and want to swing like some drunken asshole for longer periods of time. If you keep your end low you can focus on attack stats as needed.
Vit goes as high as possible up to 50. I'd keep it at 20-25 no more until you have your attack stats covered.
If you use a non-physical (ARC/BLO) stat with a physical one, then it's easier to increase the physical one first. Maximising your SKL is a good strategy as some weapons only scale off SKL. Practically no weapon scale off exclusively STR, not even the hammer (which is still the best weapon in the game, like every other weapon).
As one might expect the most powerful build is really just a newbie quality build that will use Ludwig's sword to the greatest effect, as STR and SKIL both pile on physical damage. It's also the most boring build, too. A much cooler option is to run around like a true bloodtinge edgelord with a katana and cut yourself with it to minimally increase your damage output while you take a iado draw stance that will uterly surprise and baffle your enemies when they decide to smash you down with extreme force. I call this build the Master of the Great Cut ; he wears a Top Hat, as all my builds do.