Royal Knight Loretta (LVL1 NG+7 no talismans/buffs/skills)
15playlist: https://www.youtube.com/playlist?list=PLBm8s64hbk30zO2hps1YcF_BIY6gMlPy2
This phantom version is necessary for Ranni's quest, which leads to some other main bosses later. There are other bosses that you can fight for some NPC interactions, but this one is actually needed for the quest.
This fight turned out okay, but I fumbled my inputs at the end. You can just run to the side under the horse's stomp to get an attack. Rolling and then trying to attack isn't always safe, but the boss only needed the last hit anyway.
I kept trying to find more openings to attack more than once, but every time I experimented with it, she kept pulling out some brand new tricks. It's a weird fight in which a lot of her moves look and function the same, so I just went on intuition for the most part.