Raven (Stellar Blade)

By far the most difficult battle (for me, anyway) in the game and a memorable boss across the many games I've played. Probably took more time than all other bosses combined. I did use the accessibility controls to guarantee that I won all the QTE events because somehow I could never win them legit no matter what I did. I wish I had upgraded my shield breaker beta attack to enable me to down her, that might have helped a little.
After this, the final boss was pretty easy.
It felt great winning this in the end.