The part below the band logo is based upon a section of a larger engraving called "Death on a Pale Horse (Revelation)" by Gustave Doré.

According to Steve Huey of AllMusic, "Even if the keyboards mostly just outline basic chord changes, they add a melancholy air to all the furious extreme sounds, turning the one-note ugliness of black metal into something emotionally complex.

"[5] Kerrang said, "Proving that [black metal] wasn’t all about primitivism, instead the composition here is technically and creatively staggering, with ethereal keyboards adding a freezing atmosphere.

They also expressed a fascination with the Viking age, Tolkien's literature, story of Dracula, as well as "everything related to Transylvania, the Carpathian Mountains, the dark corners of Eastern Europe, and folklore."

[2] In his review, Steve Huey of AllMusic gave the album five stars out of five, writing, "In the Nightside Eclipse resoundingly demonstrated that there was real musical substance and ambition in the world of black metal.

This is still, at its core, a harsh, obscenely heavy record, and one only needs to place themselves in the maelstrom of tracks like "I Am the Black Wizards" to realize there is more than just symphonies at work here.

[1][11] Kyle Ward of SputnikMusic credits Emperor with "[taking] the genre in a direction now seen as a natural extension of black metal's sphere of influence.

In 2005 Decibel Magazine adopted the album into their hall of fame, writing that "upon its release in 1995, In the Nightside Eclipse established Emperor as the reigning masters of a more complex, atmospheric style of "symphonic black metal".

[17] Matt Heafy of Trivium wrote that "Emperor had crafted a unique sound in its combination of the classical with modern metal conventions that had not been executed with such precision before.

For the reissue, the opening tracks "Intro" and "Into the Infinity of Thoughts" were combined, whilst the album was packaged in a paper slipcase covering the traditional jewel case, with both featuring the same artwork.