Nocturne features demons, spirits, and beasts that I've already seen in the Persona series but this time in a much different context. Persona is about the human characters. The demons themselves are generally secondary and serve merely as sources of power for the game's characters. In Nocturne, the demons are integral to the plot and to the theme and atmosphere of the game. Demons like Matador, Daisoujou, and Mizuchi feel impactful and memorable not just because of the mythological beings they represent, but because they exist in the game as characters, as powerful entities which the demonic protagonist must defeat. When the demi-fiend (the aforementioned protagonist) encounters Matador by surprise in a darkened hallway, as he grasps him by the legs and drags him into some hellish dimension--it is chilling. It is memorable. And the twisted music that accompanies this encounter (and future fiend counters) is positively spine-tingling.
Although Shin Megami Tensei: Nocturne doesn't contain some of the features I loved about the Persona series, it more than makes up for it with atmosphere, challenge, and variety. There are tons of demons to fuse and try in Nocturne, all of which can be placed into your active or reserve party. Reserve party members can contribute outside of battle with healing and utility spells like Estoma, which reduces the encounter rate--or Liftoma, which nullifies the effect of damaging floor tiles. The demi-fiend himself learns skills through Magatama, strange parasites that can be ingested. They also impart resistances (and frequently weaknesses) to various elements, as well as bonuses to certain stats. It is in this way that the player can customize the protagonist to their liking with up to 8 total skills. There isn't as much diversity in the protagonist's playstyle as in Persona 3 and 4, but considering the variety available in party members, I can't fault the game for this.
Suffice to say, it's a wonderful game and I can't wait to play other titles in the main series. I just might backtrack and start from the very first one.