head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Practiced Mastery
A grim 2D action metroidvania steeped in religious horror.

Execution · Practiced Mastery
A musou-style hack-and-slash letting players mow down hordes as One Piece characters.
Blasphemous leans Execution (Practiced Mastery); One Piece: Pirate Warriors 4 leans Execution (Practiced Mastery).
Blasphemous leans a little harder on execution, though the gap is small.
Blasphemous
Punishing 2D combat and platforming
One Piece: Pirate Warriors 4
crowd-clearing combo execution against hordes
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Blasphemous
Scripted bosses
One Piece: Pirate Warriors 4
enemies are scripted mobs, not adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Blasphemous
Static world
One Piece: Pirate Warriors 4
minimal randomness in stage encounters
Blasphemous leans a little harder on optimization, though the gap is small.
Blasphemous
Rosary bead builds and routing
One Piece: Pirate Warriors 4
character builds and combo routing are learnable
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.