exploration wise, nioh lose to souls because random loot and dark souls 1 at least have better levels, even nioh isn't that bad as people made it seem to be.
combat wise though, it is alot more fun than dark souls. the variety is just astonishing. you have 7 weapon types, stances, stands*ahem* i mean guardian spirits, skills and stats. i am only 2,5 hours into the game and feel like the combat and character building have immense depth.