Their weapon Buffs do not scale to Elden Ring Runes strengthen dexterity, so you don't need to invest into anything else to make them work. Nothing fancy, but what if we wanted to combine it with the frozen lightning spear, now that's much more difficult as you need at least 34 points into Faith to get the Frozen Lighting Spear incantation. There are also no great options to easily get a decent amount of incantation scaling while investing into strength or dexterity.

While the dragon scale blade leans more towards a dexterity scaling weapon so you don't waste the dexterity investment, as it gives the incantation cast speed. You will still have a relatively low incantation scaling.

Hybrid builds are always that hungry too and holding one single Katana really isn't the best weapon option when the weapon Arts is locked into the ice lightning sword. A move that won't really land in PvP and isn't all that great in PVE outside above.

Lightning infusion and Ash's scale to dexterity, but the lightning incantations scale to faith, cold infusion depends on the weapon but it will scale to shrink dexterity and intelligence, cold bullet arts scale to dexterity and intelligence, sorceries that apply Frost scale to elden ring items buy online intelligence.