Of course, the music genre is always questionable for the bands with such a diversified discography as Devilish Impressions. Nevertheless, I would suggest to change the genre to "Experimental" because it is intrinsic to their music and attitude. The word "Symphonic" can describe well the Simulacra album, but not the rest:
- the guitars/synths on Eritis Sicut Deus and Plurima Mortis Imago sound very "industrial";
- the Diabolicanos' guitars and synths sound "progressive";
- barely existing, the Adventvs' synths are on the background, sounding more "atmospheric".
Of course, the music genre is always questionable for the bands with such a diversified discography as Devilish Impressions. Nevertheless, I would suggest to change the genre to "Experimental" because it is intrinsic to their music and attitude. The word "Symphonic" can describe well the Simulacra album, but not the rest:
- the guitars/synths on Eritis Sicut Deus and Plurima Mortis Imago sound very "industrial";
- the Diabolicanos' guitars and synths sound "progressive";
- barely existing, the Adventvs' synths are on the background, sounding more "atmospheric".
Source/Evidence:
Simulacra samples: https://www.youtube.com/watch?v=mKsgJI_111o
Diabolicanos samples: https://www.youtube.com/watch?v=QzhG9-ZmvRQ, https://www.youtube.com/watch?v=ibpg9VYdYLY
Plurima Mortis Imago sample: https://www.youtube.com/watch?v=AAwVKT_FUlU
Adventvs sample: https://www.youtube.com/watch?v=FacuWzRbro0
You may also consider that the band sometimes refers to themselves as "Experimental Black/Death Metal" (like here https://www.youtube.com/watch?v=06P7TUoy-j4)