Why so many [Weapon buff] builds go so heavily into faith?

For how AR and Damage Reduction works, to achive maximum damage the best way is to soft cap both a "physical" and a "magic" stats.

The question is a little more complex, I'll try to break down assuming we want to stop at soul level ~ 120.

Weapon Buff are a strong resource, but they are not always the best way to go. They works the best with weapons that hit fast, wich usually have lower AR to compensate. Of course, they works extremely well with double weapons ( Twin daggers, Sellswords Twinblades, Onikiri and Ubadachi ) since they hit multiple times.

Since we are stopping at SL~120, we had to make choices. Assuming we are Knights as starter Class, we will have something like:

• Vigor 30
• Attunement 10
• Endurance 30
• Vitality 30
• Strenght 13
• Dexterity 12
• Intelligence 9
• Faith 9
• Luck 7

For a Soul Level of 61 and ~ 60 levels to spend.

I've put 30 in Vigor/Endurance/Vitality to assume we have a total of 90 points between these 3 stats - you can go for example 40 in vigor and 20 in vitality -, but most of the time you want to spend here these points since you need to not be one-shotted or not able to attack multiple times with your weapon. The other stats are at their starting values.

I'll cover 3 simple ways to build from this point and I'll use the Broadsword and the Greatsword as examples and assuming we use the Clutch Ring of the same element of the buff to get +15% elemental damage for that type in PvE or 8% in PvP.

• Reach the minimal requirement of the weapons of choice, raw infuse it and then spend everything in the caster stats.

This will give you Low Base damage and High Buff damage.

How to spend our 60 points: reach the prerequisite of your weapon then put all of them in Intelligence/Faith.

Broadsword path ( Strenght 13, Dexterity 12, Intelligence 9, Faith 60, Raw Infused )

Base AR: 322

Lightning Blade with Yorksha's Chime : ~ 234 Bonus AR => 269(PvE)/253(PvP)

Total: 591(PvE)/575(PvP)

Greatsword path ( Strenght 28, Dexterity 12, Intelligence 9, Faith 54, Heavy Infused )

Base AR: 514

Lightning Blade with Yorksha's Chime : ~ 213 Bonus AR => 245(PvE)/230(PvP)

Total: 759(PvE)/744(PvP)

• Reach the softcap in one "physical stat" ( Strenght or Dexterity ), infuse the weapon with the proper infusion ( Heavy for Strenght-oriented or Sharp for Dexterity-oriented ) and the spare point in the relativa casting stats.

This will give you Medium Base damage and Medium Buff damage.

How to spend our 60 points: reach ~ 40 in both Strengh or Dexterity and Intelligence or Faith.

Broadsword path ( Strenght 13, Dexterity 40, Intelligence 9, Faith 40, Sharp Infused )

Base AR: 417

Lightning Blade with Priest's Chime : ~ 174 Bonus AR => 200(PvE)/188(PvP)

Total: 617(PvE)/605(PvP)

Greatsword path ( Strenght 40, Dexterity 12, Intelligence 9, Faith 40, Heavy Infused )

Base AR: 580

Lightning Blade with Priest's Chime : ~ 174 Bonus AR => 200(PvE)/188(PvP)

Total: 780(PvE)/768(PvP)

• Forgot about the buff and spend everything on Strenght/Dexterity and go for a quality build or focus only on one of them.

This will give you High Base damage and Low Buff damage.

How to spend our 60 points: all in Strenght and/or Dexterity.

Broadsword path ( Strenght 13, Dexterity 72, Intelligence 9, Faith 9, Sharp Infused )

Base AR: 468

Gold Pine Resin : 95 Bonus AR => 110(PvE)/103(PvP)

Total: 578(PvE)/571(PvP)

Greatsword path ( Strenght 73, Dexterity 12, Intelligence 9, Faith 9, Heavy Infused )

Base AR: 630

Gold Pine Resin : 95 Bonus AR => 110(PvE)/103(PvP)

Total: 740(PvE)/733(PvP)

Until now we are talking only about the AR of your weapon. But we had to remember about Defense and Absorption.

Defense and Absorption ( expecially Defense ) have their own extremely articulate formulas, but we can simplify in: Defense reduce the damage taken by 10% to 90%, based on the magnetudo of the damage received. Absorption reduces the damage taken - after Defense calculation - by a fix %. Taking again the examples of before, assume we found an opponent with 145 Physical Resistance, 150 Elemental Resistances, 30 Physical Absorption and 20% Elemental Absorption.

Full Faith/Int

• Broadsword

Base AR: 322 => 156

Buff AR : 269 => 136(PvE)/253 => 123(PvP)

Effective: 292(PvE)/279(PvP)

• Greatsword

Base AR: 514 => 277

Buff AR : 245 => 118(PvE)/230 => 106(PvP)

Total: 395(PvE)/383(PvP)

Even split

• Broadsword

Base AR: 417 => 212

Buff AR : 200 => 83(PvE)/188 => 74(PvP)

Effective: 295(PvE)/286(PvP)

• Greatsword

Base AR: 580 => 322

Buff AR : 200 => 83(PvE)/188 => 74(PvP)

Total: 405(PvE)/396(PvP)

Full Physical

• Broadsword

Base AR: 468 => 245

Buff AR : 110 => 22(PvE)/103 => 18(PvP)

Effective: 267(PvE)/263(PvP)

• Greatsword

Base AR: 630 => 358

Buff AR : 110 => 22(PvE)/103 => 18(PvP)

Total: 380(PvE)/376(PvP)

Conclusions :

Going full in Int/Faith give you a good damage while buffed, but the lowest damage when unbuffed. It's the best if you want more spells and not rely only in your buffed weapon.

The even split gives you a nice good damage and the best damage when buffed.

The full Strenght/Dexterity gives you a very high base damage even when unbuffed.

Lightning blade isn't "better". It's just easier to acquire. Between all the weapons buff, Darkmoon Blade is usually "the best", since it gives the same damage of Lightning Blade but it's Magic Damage wich usually has a lower defense.

After a bit of digging, I think I can answer my own question.

It all boils down to the spellbuff that scales with intelligence for sorceries or faith for miracles (for pyromancy it scales with both, but it would require heavy investments for both stats): in short, after hitting the dexterity softcap, it is better to invest into a "magic" stat (int/fth) to increase the potency of a weapon buff.

Example:

Sharp Sellsword Twinblades +10 at 40 Dex deal 365 damage. At 60 dex, they would deal 387 - so for the cost of 20 points you get 22 points of extra damage.

But then we can buff them: If we assume (incorrectly) that all spellbuffs require 10 int/faith then:

With 10 int and +10 Sorcerer's staff we could add 95 magic damage or 95 lightning damage with talisman +10 (or 110 fire damage with +10 Pyromancy flame). If we invest the same 20 points in int or faith (so 30 int or 30 faith total) we will have:

• 133 Magic damage with Greater Magic Weapon and sorcerer staff => 38 extra points of damage
• 157 Lightning damage with Sunless Talisman and Lightning Blade miracle => 62 extra points of damage

So it is much more efficient to start investing in secondary int/faith rather than keep pushing the dexterity.

Even more: let me look at the 40 dex 60 int/faith (investment of 50 points).

• At 40+50 = 90 dex sharp selswords +10 deal 431 damage. Extra damage = 66 damage
• At 60 int we have 214 extra damage from Greater Magic Weapon
• At 60 faith we have extra 230 extra damage from Lightning Weapon

tl;dr

Diminishing returns make investing into faith or int more worthwhile.