head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Dracula stalks a modern city in a combo-driven action sequel mixing whip combat with stealth detours.

Execution · Practiced Mastery
Zelda-meets-God-of-War action adventure starring the horseman War.
Castlevania: Lords of Shadow 2 leans Execution (Practiced Mastery); Darksiders leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Lords of Shadow 2
Whip combos and dodge timing carry combat encounters
Darksiders
combo-driven combat with dodge timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Lords of Shadow 2
Bosses cycle scripted phases; stealth foes patrol fixed routes
Darksiders
enemies are scripted
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Lords of Shadow 2
Modern-city detours are authored, not random
Darksiders
world and bosses are fixed
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Castlevania: Lords of Shadow 2
Void/Chaos resource juggling and mastery grind are mappable
Darksiders
Zelda-style dungeons and upgrade routing
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.