This case was designed only for using flexible materials, do not try to make any of these models with PLA, ABS or any rigid filament. This phone is articulated, so the case needs two parts to work: one "back" for the keyboard part, and one "front" for the screen. You can combine any front part with any back part, but not with the "alwaysopened" or the "alwaysclosed" models, because they are designed for holding the whole phone in a fixed configuration. If you have any request on the design just ask me.
The "lovecraft" model was recicled from an old pen drawing I've made in a supermarket ticket, which I used as a "skin" of that phone. It is not copied from an specific image, but inspired by some artwork from Lovecraft literature.
This is part of an update for the 2020 Valentine's Day, in which I add for most of my phone cases a "heart" version; a model with a hole in the back side with the shape of a heart.
For other phone cases check this.
Here is the explanation of the files names:

Aired: It is widely opened in the back so that the phone can dissipate the heat easily.
AlwaysOpened: If you have the same problem as me, that when you open or close the phone's keyboard the touchscreen stops working, this case can keep the keyboard opened, preventing it from closing.
AlwaysClosed: Similar to the opened one, this model avoids opening the phone, keeping it as an non physical keyboard phone.

I spend part of my time making these models, letting them available and free for everyone. If you want to support my work, you can contribute with me here:

Found 10 3D-models for “erics” across many websites

Xperia Arc S phone holder

5x5 , 8x5, Sandwitch style Z Coupling, internal nut lock, conical hole

Key from SSC-02 Ericsson

Niros TRX 3001 display panel base

Aurora R.A.M mount compatible holder.

"Heavy Duty" bumper case for Xperia Z1 compact

sony/ericsson phone charging table

Movember Foosball Trophy

Sony Ericsson Xperia Mini Pro sk17 case

Basic Vintage GSM/Analog Mobile Phone Stand