Also just food for thought, there are variants depending did you get the living statue or not (also depending on Miyuki's status), and some stuff behind killing Marcus instead of giving him to Tamara.
Oriana: Don't smack Gertrud's ass => No waters blessing, and don't ask help from the merfolk. The relationship with Maria doesn't matter.
Bruce: Visit Bruce before Ragnar and Helga. Aka less drinking buddies.
Kiri: Oh boy so many ways. Get the "Living Statue" spell and kill Marcus, allowing Tamara to take Kiri's life as payment. OR, submit to Tamara's will and say No when she wants Kiri's life, although this leads to a bad end. Otherwise you need to get Miyuki to betray you (aka turn her down and tell the Oni to take over the seal)
Tamara: Don't get the living statue, have Miyuki betray you, and be allied with Gorgons. Get the living statue spell, Kill Marcus, don't submit to Tamara's will, and say no when she wants Kiri's life.
EDIT: cause I don't like to do multiple separate posts without a good reason.