If you want to gain strong combat effectiveness here, you can only obtain some powerful equipment and other methods through your own operations. If you want to know how to unlock the end-point achievement of Nine Days Evolution to improve your combat effectiveness and make yourself stronger, then follow the editor of Sourcecode.com and take a look at this guide. I believe it can give you the answer. .
1. We need to go to the map location of the Natural Disaster Research Institute to open the Black Butterfly puzzle. Please refer to the picture below for the specific location.
2. At this location, follow the route in the picture below until the iron wheel rolls into the room.
3. Enter the gap after rolling the iron wheel to find the hidden information.
4. You can unlock the achievement after interacting with the hidden information. Please note that the hidden location needs to be obtained before triggering the escape plot.