Can't get the second ending in Rea's Route.

[xX420_demonkillah_96Xx]

I finished all the other routes and side stories and got the first ending for Rea's route but I can't seem to get the second ending or unlock the epilogue for her route. I keep choosing the "sought the truth" option but the first ending just plays. Is there something I'm doing wrong?

[Medicine Melancholy]

You need to see all optional scenes with Rusalka for second ending. Check Guides for right choices. Also better start with "New Game" option instead of picking Rea route from route select.

[Calamitous]

You have to wait for the credits to be done in order to get the last bit of story and then you unlock it.

[baba.scoop]

You should follow the choices describes in this walkthrough:
https://gareblogs.wordpress.com/2017/06/01/dies-irae-amantes-amentes-english-walkthrough/

It worked for me.