Marandahir
Crown-Forester (he/him)
See, that was a cool think about 4e classes that I feel was lost in 5e, with the sole exceptions being the Fighter and Ranger. Your key ability score wasn't locked to a single option.In 4e I played a Warforged Star Pact Warlock who had been partially built out of a meteor! Back then, Warlocks could use CON to cast their spells and it worked perfectly. He was crazy and heard things in his head...
I think a lot of people would have been less upset about Aberrant Mind/Psionic Soul Sorcerer being "the Psion" if Sorcerers could cast with Int instead of Cha, for example.
In 4e, the Warlock could be Con/Int, Cha/Int, or a Cha/Con dual caster, depending on your choice of powers…
But that leads to a lot of challenges in creating spells for each type of Warlock. In 5e terms, I'd just let them choose their casting ability score. But Con isn't a casting score anymore because a Con-Caster (or Con-attacker, like the 4e Battlemind i.e. Psychic Warrior was) is just too bulky a concept in 5e. Con is the one score in 5e that everyone wants as their 2nd or 3rd highest ability score.