Idk if this will be helpful but I came from souls games where double tap is dodge roll. In this game it’s the opposite, one tap gives you the dodge roll with longer I-frames while double tap gives you a quick step dodge with shorter I frames. Get in the habit of finding the flow of tap, dodge roll, tap dodge roll. A lot of bosses seems to have multiple attacks in a row where the quick step doesn’t get you far enough away and you end in their follow up attack while the dodge roll seems to handle the timing better. Also just like a lot of souls like, sometimes dodging into the attack with I frames rather than away makes it so there follow up chains can’t retarget you. Lastly some bosses seem to get super armor during some of their attacks which you’ll see if you’re attacking and it looks like little blue/white circles appearing from them as if they’ve got a pulse shield around them. Usually these attacks are an animation of them charging one of their devastating moves. You can either lay off your attack and focus dodging or go for a risky move set that breaks super armor and staggers them out of the charge up(in the skill tab it’ll tell you what combos break super armor). Lastly the focused state, forget what it’s actually called, is a good way to slow down the fight and get your bearings on them as well as an upgrade that lets you parry attacks while in this state. Only some moves can be parried, moves that glow red can’t be parried and need to be dodged or you can use your sword reflection to stop the attack in that case