4/8
Killing the Elf Princess is an option that doesn't need to be said.
It's the most helpless move when there's really no other choice, because it only eliminates the threat but doesn't bring any benefits to them, and even wastes his 70+ draws.
What Reji hopes for the most is that, after knowing all the information about the Elf Princess Vielsia, he can easily "take an open-book test" and raise her favorability, making her willingly join his side. Reji is slightly confident in this, after all, he still has another trump card - Reji had Eris preserve the bodies of those elves who were tortured, and they have not been burned or destroyed.
Of course, if the Elf Princess is really very determined and unshakable, then having Eileen corrupt her into a Succubus is also barely acceptable to Reji.