Is there a list of what the skills the weapons provide are somewhere for planning purposes.
Not yet (I think). May as well try to translate and guess it. (Anyone who notices I made a mistake, please correct in later posts )

Arthur:
Sword (ATK) - Absolute Monarchy cooldown from 6T to 5T
Axe (HP) - Double Attack Up added to Avalon's Guidance (D frame?)

Andromeda:
Staff (ATK) - Def buff from Cursed Canting Chains increased by another 20%
Spear (HP) - Adds regen (350/T for 2T) after using Resuscitation

Mordred:
Sword (ATK) - Adds mode gauge reduction effect to Outrage
No idea if it's a buff for the soul, or one time reduction like with for example
Archangel summon
Sword (Glaive?) (HP) - Outrage dispells one buff from the enemy

D'Artagnan:
Gun (ATK) - Snatch 3rd effectiveness up
Gun (HP) - As mentioned by others, Sniper Shot up to 30% ATK debuff

Joan of Arc:
Sword (ATK) - Cooldown of Orelean Call down from 8T to 6T
Spear (HP) - Voice of Gods gets further 20% dmg reduction (60% total?)

Hercules:
Axe (ATK) - (Here I'm not really sure if it's the right skill) - Indomitable - adds 30 burst gauge
Bow (HP) - Full Break buff (Cap 1 million)

Solomon:
Sword (Glaive?) (ATK) - ???
Staff (HP) - stronger Book of Raziel, smaller cooldown

Siegfried:
Sword (Glaive?) (ATK) - stronger Overdrive
Hammer (HP) - Morale boost - adds attack buff for everyone

Morgan:
Staff (ATK) - ???
Arcane (HP) - ???

Shingen:
Spear (ATK) - Roaring Blaze - Burst gauge increase up from 20 to 35
Bow (HP) - Provisional Forest - Ally burst dmg up?

Okay... So... Would someone be so kind and confirm the above, then clarify the "???" ? Especially for Morgan.