I always thought Wyll should be Pact of the Blade because he has a Rapier, and warlocks aren't proficient with rapiers. With Pact of the Blade, he'd have a magically summoned blade that could take the form of a rapier.
I think so as well, especially considering that Pact of the Blade is a PHB option if I'm not mistaken while Hexblade is not.
