In order to obtain this achievement, you must infuence Nona so she and Ren end together. There are three key moments in which you can do it, and an optional thing that
IMPORTANT: Seems that "I am the firestarter" is giving trouble to some people when attempting this achievement at the same time. So, when doing this
, be nice to the other characters or this won't unlock.
-
At the beach, when Ren and Jonas are going to jump the fence, don't follow them yet.
Go talk to Nona and tell her nice things about Ren.
- Not sure about this, but could influence the result too. When
in Harden Tower, choose Jonas as your companion so Ren and Nona stay together.
-
At Adler's Estate, when searching the house,
go talk to Nona near the boat and, again, talk about what a nice guy Ren is.
- Finally, when you are
at Bridge Stand in order to send the signal that opens the bomb shelter, you'll enter on another of those time loops. Before using the tape recorders in the bridge,
talk to Nona and tell her that
Ren knew she liked him.
I believe that completing 2 of these 3 conditions is enough (I never did the first one), but complete all 3 just in case. If you meet these requirements, you'll obtain the achievement during the "stat count" before the credits.
For a guide on how to get all the ending achievements in the lowest number of playthroughs, click here