I've always wondered about creating a character who trains to use every spellcasting ability.
The publication of Bigby Presents: Glory of the Giants introduces the possibility of using Strength in a ranged spell attack "as the spellcasting ability". The Keenness of the Stone Giant feat can increase Strength by 1, and the Stone Throw feature says:
As a bonus action, you can take a rock and make a magical attack with it. The attack is a ranged spell attack with a range of 60 feet that uses the ability score you increased with this feat as the spellcasting ability.
And with the spells selected with the Aberrant Dragonmark feat (from Eberron):
Constitution is your spellcasting ability for these spells.
This suggests the possibility of combining further feats or multi-class spellcasting to collect all six spellcasting ability scores in one (terrible?) character … if Dexterity can be used in a similar way.
The Way of the Sun Soul Monk has a strangely worded Radiant Sun Bolt ranged spell attack feature which doesn't mention a 'spellcasting ability' but does say:
You gain a new attack option that you can use with the Attack action. The special attack is a ranged spell attack with a range of 30 feet. You are proficient with it, and you add your Dexterity modifier to its attack and damage rolls.
Are there ways of getting Dexterity as a named "spellcasting ability" anywhere?