So, inspired by all of you I tried.
I didn't pay attention to the time I took, but I took a long break after Romy killed me for the first time.
I wouldn't dare a +4, but maybe next time... I did use Luna's inspiration, lore and daggers for the AVs fight. First attempt at the last mission Imperious messed all up, so I had him gently killed before approaching Romy again.
I pulled Romy and dealt with the Essences first, which took me a while (would there be a better way to deal with them?).