These are all the women you can marry to Eudenus before completing the Lava Cave and getting the 8th Seal. After completing the Lava Cave, Eudenus will have different things to say depending on who you married him to. If you don't marry him to anyone, then he'll marry his maid Pepe. Eudenus will also have different things to say during the ending depending on who he married. Any other female character not mentioned are not available at the time of such sidequest.

Unlockable	How to unlock
Get ending variation B	Marry Yuma, Jenka, or Melina
Get ending variation C	Marry Iris
Get ending variation D	Marry no one.
Unlock the treasure room upstairs, get ending variation A	Marry Nikita