If you’re familiar with FROM Software games, then you’re right to assume that Sekiro is Dark Souls set in medieval Japan. While the signature masochistic and demanding difficulty from the developers’ popular titles are still incorporated in the game, you can consider the game as an amped-up Tenchu with emphasis to stealth and strategic disengagements to gain advantage.
Enemy encounters will always keep you on your toes as even the most basic enemies can easily slice through your life (vitality) bar if you’re not careful. The Wolf (game’s protagonist) can also get overwhelmed by multiple enemies so learning when to disengage and thin out enemy numbers is essential in the game.
Combat will always require quick reactions and conservative, precise strikes. Deflecting/parrying enemy attacks are essential in creating openings to instantly kill them or heavily damage bosses. Evading/dodging will not only play as defensive move, but can be used for aggressive re-positioning as well.
Sekiro is a lot more forgiveable and manageable than the other Souls series but make no mistake, the game will still punish players that underestimate, act too aggressive, or being too passive. The game can be demanding at times so learning from mistakes and dying too often is still an important aspect of the game. There’s no difficulty adjustment options in the game so what you see is what you get.