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
The fastest mainline Souls, distilling the formula into aggressive boss duels.

Execution · Practiced Mastery
The series' action peak, with flashy drive forms and superbosses that built a lasting challenge-run community.
Dark Souls III leans Execution (Practiced Mastery); Kingdom Hearts II leans Execution (Practiced Mastery).
Dark Souls III leans a little harder on execution, though the gap is small.
Dark Souls III
fast roll timing against aggressive scripted bosses
Kingdom Hearts II
Revenge values and Data fights demand precise play
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dark Souls III
PvP invasions exist but are optional
Kingdom Hearts II
Even superbosses run scripted, mappable patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dark Souls III
fixed encounters converge after first sight
Kingdom Hearts II
Fully visible action systems
Dark Souls III leans a little harder on optimization, though the gap is small.
Dark Souls III
movesets and builds are fully mappable
Kingdom Hearts II
Forms, abilities, and boss study reward labbing
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.