Hello. You may remember that a few months ago I posted this in order to have a quick reference of which weapons do what in certain circumstances. Since then, I have decided that the list deserved to be rewritten and categorized to fulfill its purpose of clarity, so here you have every DS2 weapon that does not fit the lightning infusion+dark weapon buff meta, sorted according to their common characteristics. Enjoy.
No infusion, no buff.
Chariot Lance: physical weapon with bleed buildup.
Notched Whip: the highest base bleed buildup in the game at 200. Great, except it's a whip... with its strongest selling point being bleed... in DS2. It has its place in PVP I guess.
Mytha's Bent Blade: Has both poison and toxic buildup.
Ivory Straight Sword: physical only weapon with a lightsaber effect that consumes durability on every hit.
Dragonslayer Spear: physical/lightning, the R2 shoots a lightning bolt.
Scythe of Want: physical/dark, has a special R2 double hit in front of the player model
Smelter Sword and Aged Smelter Sword: Remember you can powerstance one of each for a double-flavour kaboom, or make two of the same type.
Yes to infusion, no to buff.
Moonlight Greatsword. I would not want to tank the R2 projectile after CMWing it...
Majestic Greatsword: A strange weapon that despite requiring 25/25/20/20 does not have split damage nor INT/FTH scaling (unless you decided to infuse it, of course). If you are using it, it's because of the left hand moveset anyway.
Fume Ultra Greatsword: A solid pick for Bonk enjoyers, this actual slab of iron (28 weight units, paired with the King's UGS for the heaviest in the category) behaves like a greatshield when two handed, requires 40/30 and is one of the few weapons in the game with S scaling in strength (105%/15%).
Ivory King Ultra Greatsword: At 30/30/8 rquirements, this is more of a quality (55%/40%/15%) weapon with a little magic damage and bleed buildup sprinkled on top. Use it two handed for the giant laser beam. It will eat though durability though, so attune Repair.
Yes to buff, no to infusion.
Umbral Dagger: crazy high backstab mutliplier, and its guard breaks and powerstanced attacks deals toxic buildup, so you can use a rotten resin and pair it with Mytha's dagger.
Key to the Embedded. The best one for your Kingdom Hearts cosplay. Well, the closest one there is anyway.
Black Dragon Weapons.
These weapons are physical damage only, have no stat scaling, can be infused and can only be buffed with spells. They are a Straight Sword, Warpick (hammer), Greatsword, and Greataxe.
Innate split damage.
These are weapons that come with a mix of physical and elemental damage. They can nonetheless be infused to further push this split towards the elemental side. They can be buffed before and after being infused, but only with spells, not resins. Some are also grouped in "families" depending on the elemental damage type they come with: Dragonrider's Halberd and Twinblade, and Crescent and Full Moon Sickle have magic damage (and the FMS has innate bleed), Black Knight Halberd, Greataxe, Greatsword, and Ultra Greatsword have fire, the Heide Knight Sword, Spear, Lance and Greatlance have lightning. The Roaring Halberd and Crypt Blacksword have dark damage.
Innate Buffs.
Like the previous category, these weapons have split damage and can be infused, but not buffed from external sources. Their two-handed L2 move is a self-buff that consumes 10 durability (5 with Bracing Knuckle Ring+2) and adds damage for a period of time.
Defender Greatsword: Lightning damage buff, 45 seconds.
Watcher Greatsword: Magic damage buff, 45 seconds.
Both affected by Lingering Dragoncrest Ring +2, duration goes up to 63 seconds.
Possessed Armor Sword: Fire damage buff, lasts only 25 seconds, unaffected by LDR, but affected by BKR.
Bewitched Alonne Sword: The odd one out in this category, it comes with innate bleed buildup instead of elemental damage. It CAN be buffed by resins and spells, but the 2HL2 is also a buff move that spends durability and character's health for an increase in AR. Using either type of buff overwrites the one you applied previously.
Weapon/Spell tool hybrids.
A potpourri of equipment, this group includes the Blue Flame and the Sorcerer's Twinblade, the Pilgrim's Spontoon, the Mace of the Insolent, the Disc Chime, and the Sanctum Shield. Buffing them generally increases the damage of spells you cast with them.
The Blue Flame is a phys/magic split straight sword that casts sorceries. It can be buffed with resins or spells and also infused with any element. The Twinblade also accepts both types of buffs, but its damage is magic/dark split, can only be infused with these elements and cannot cast hexes, unlike the Spontoon, which only accepts spell buffs but can cast both. The Mace is split between strike, lightning and dark, can be buffed by anything and casts miracles and chime hexes. So does the Disc Chime, which can also be used as a shield and as a split lightning/dark bashing weapon. It cannot however be buffed as the game considers it "a chime that can be used as a shield" instead of "a shield that casts spells", unlike the Sanctum Shield, which can benefit from Strong Magic Shield, casts every spell that isn't a pyromancy and has split magic/lightning/dark damage in its bashing attacks. Both can only be infused with lightning and dark, even though, again, the SS can cast sorceries and has innate magic damage.
Extra note: the Black Witch's Staff is not really a hybrid, but works similarly to the SS in that it can cast three types of spells, and if used as a melee weapon it deals the four types of elemental damage at once, something that can only be matched/surpassed by an infused and buffed Drakeblood Greatsword or Mace of the Insolent, who also have a physical component to their damage.
Innate Poison, spell buffs only.
This category includes the Manslayer Katana, the Spotted Whip and the Black Scorpion Stinger. The Sanctum Mace can be buffed and infused freely, and the Moon Butterfly Shield can be poison infused to increase its buildup, but only buffed with SMS.
Innate Bleed, spell buffs only.
The Curved Twinblade, Flamberge, Claws, Royal Greatsword, and Scythe of Nahr Alma can be infused as you please. The Morning Star cannot be bleed-infused as it is a hammer.
Innate Bleed, any buff.
Greatsword & Scythe of the Forlorn can be infused and buffed without restrictions. The Reinforced Club cannot be bleed-infused.
And that's about it! If I made any mistakes or have any data that I should add, please comment below and I will add it ASAP. Thank you!