Pact of the Blade Locks kinda sorta suck in this edition, but also not really?
The Eldritch Scythe does deal 1d8, like a longsword, but the damage is Force, and therefor pretty much infinitely preferred over slashing. It's also magic damage from level 1 onward.
If you do choose to make a Bladelock, Eldritch Scythe is, honestly, not a good choice for your Eldritch Blast. What is, is Eldritch Disturbance.
As a light fighter with, say, a Longsword and a Shield (For defensive and parrying) or whatever, Eldritch Disturbance gives you an at-will saving throw targeting function. Yeah, your target is more likely to make a save than dodge a ray, but if you're swinging at something with an AC high enough that melee attacks just aren't cutting it (Get it?) then a save for half effect means assured damage. Particularly since high armored creatures tend to have lower wisdom saves in comparison to, say, dex for fireballs.
Skip over Agonizing Blast to instead go for Eldritch Riposte so you can use Disturbance as a reaction for spell points, and either Armor of Shadows or Eldritch Warrior for tougher armor. Grab Lifedrinker, obviously. Go for Eldritch Grasp if you wanna roleplay Darth Vader and force-choke folks...
And absolutely go for Eldritch Prism. 20ft cube Eldritch Disturbance compared to a 60ft line scythe or a 30ft cone ray or a single target hold for whip...
As a melee character with medium, light, or no armor, you've gotta hedge your bets. If you wanna do AoE melee damage with the scythe, don't bother with Pact of the Blade and aim for Armor of Shadows, instead.