how do i beat royal knight loretta?

i've spent like 3 days trying to learn her patterns only to discover that she has none, it seems she just throws whatever attack she wants at whatever time she feels like, i've been using the bloodhound greatsword and doing the bloodhounds finesse after all of her chains then trying to dodge her counterattack, i've gotten her down to about 1/5 of her health but around that point she just starts spamming random bullshit and i barely get a chance to attack, finesse, light, or otherwise. am i doing something wrong? should i switch up my tactic? make the sword stronger so she dies quicker?