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.

Optimization · Pure Optimization
The genre-defining metroidvania with deep RPG systems.

Optimization · Pure Optimization
Gentle action JRPG where building your kingdom matters more than any battle.
Castlevania: Symphony of the Night leans Optimization (Pure Optimization); Ni no Kuni II: Revenant Kingdom leans Optimization (Pure Optimization).
Castlevania: Symphony of the Night leans a little harder on execution, though the gap is small.
Castlevania: Symphony of the Night
Forgiving action combat
Ni no Kuni II: Revenant Kingdom
Simple action combat, rarely demanding
Castlevania: Symphony of the Night leans a little harder on reads, though the gap is small.
Castlevania: Symphony of the Night
Scripted bosses
Ni no Kuni II: Revenant Kingdom
No adaptive opposition anywhere
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Symphony of the Night
Item drops and rare gear
Ni no Kuni II: Revenant Kingdom
Minor equipment drop randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Symphony of the Night
Build crafting and sequence breaks
Ni no Kuni II: Revenant Kingdom
Kingdom building and citizen recruitment dominate progression
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.