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
Anime soulslike pairing pattern-learning boss fights with flexible class builds.

Execution · Practiced Mastery
The fastest mainline Souls, distilling the formula into aggressive boss duels.
Code Vein leans Execution (Practiced Mastery); Dark Souls III leans Execution (Practiced Mastery).
Dark Souls III leans a little harder on execution, though the gap is small.
Code Vein
Dodge timing and stamina management in melee
Dark Souls III
fast roll timing against aggressive scripted bosses
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Code Vein
Bosses are scripted patterns, never adaptive
Dark Souls III
PvP invasions exist but are optional
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Code Vein
Fixed enemy placement; minor drop randomness
Dark Souls III
fixed encounters converge after first sight
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Code Vein
Blood codes and gift builds reward theorycraft
Dark Souls III
movesets and builds are fully mappable
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.