Underworld

Level Up or Die! (Underworld, #1) by Apollos Thorne follows Elorion, a typical high school student who is unexpectedly kidnapped along with nineteen others and transported to the Underworld. There, a thousand-year-old succubus and a lich lord have devised a spell that grants him magical abilities and the chance to level up by battling monsters. Set in a fantasy world blending elements of magic, demons, and role-playing game mechanics, the story explores Elorion’s struggle to survive while navigating new powers and the demands of his captors. The novel combines young adult themes with science fiction and romance in a dark, game-like environment.

Through the Belly of the Beast by Apollos Thorne continues Elorion’s progression fantasy saga as he finally surpasses a critical level threshold after surviving Lord Darius’s assault. Forced to leave the Mistress’s Labyrinth, he enters the Underworld, a dangerous realm filled with demonic threats, strange magic, and shifting alliances that echo both classic fantasy and game-like role playing systems. Elorion must choose between consuming rare Blue Magic to increase his own power, strengthening his fellow captives, or challenging the ominous bone palace on his own. The novel blends elements of isekai, virtual reality–style mechanics, harem dynamics, and dark adventure as Elorion tests how far his abilities and relationships can be pushed in this new environment.

Sanctuary by Apollos Thorne continues Elorion’s progression fantasy arc as he and his party claim a damaged dungeon as their base, only to discover that survival in this game-like world is more complicated than winning battles. While an army of minotaurs gathers under the command of Mistress Nava’s captain, the group struggles with dwindling supplies, structural problems in their new lair, and the need to keep leveling in dangerous hunting grounds. As threats from demons, the Underworld, and other powers close in, Elorion must decide how to use the dungeon itself, how to shape his companions’ abilities, and whether to risk seeking forgotten magic in the depths below. The result blends virtual reality, dark fantasy, and harem elements with a steady focus on tactical choices and party dynamics.

Proving Grounds by Apollos Thorne continues the Underworld series as Elorion confronts the aftermath of the minotaurs’ defeat and the looming threat of Mistress Nava. Set in a game-like world where magic, demons, and virtual reality mechanics shape every decision, the story follows his effort to gain enough power to survive what lies ahead. As he struggles to protect Aeris and his other companions, Elorion must navigate escalating dangers that test both his growing abilities and his relationships. Blending progression fantasy, isekai elements, and a dark urban fantasy atmosphere, this installment pushes its young protagonist toward harsher choices and higher stakes.

Vampire Gate by Apollos Thorne continues Elorion’s progression in a world shaped by magic, demons, and game-like rules. Exiled from Sanctuary after enduring Mistress Nava’s punishment, he is forced into an uneasy alliance with the Head Mistress, who sends him on a dangerous mission into Lord Darius’s heavily guarded vault. The novel blends fantasy adventure, virtual reality sensibilities, and isekai-style stakes as Elorion navigates hostile powers and shifting loyalties. At its core, the story follows his determination to complete an almost impossible task in the hope of restoring the people and place he has lost.

Scorching Sun by Apollos Thorne continues Elorion’s progression fantasy arc as he steps through the Vampire Gate into the deeper Underworld, a realm shaped by demons, bloodshed, and dangerous magic. Tasked with a mission far beyond his current strength, he must rely on a lich guide and a brutal path of combat and leveling if he hopes to protect his companions and find a way back home. Blending elements of isekai, virtual reality, and urban fantasy, the story emphasizes tactical growth, RPG-style challenges, and a harem-tinged romance amid horror-inflected battles. The tone remains dark yet adventurous, focused on strategy, power progression, and the mounting cost of survival.

Underworld - Sanctuary 2.0 by Apollos Thorne continues Elorion’s story as he returns from the vampire realm to find Aeris and their allies hardened by brutal training and bound to the designs of the Head Mistress. Their alliance with the succubi offers only a fragile sense of autonomy, as every gain in power deepens their entanglement in demonic politics and virtual-reality constraints. With a forced journey to the succubi capital approaching, Elorion must push Sanctuary’s growth as a magical stronghold or accept that it will be left to fall. Blending progression fantasy, isekai, and dark urban fantasy elements, this installment focuses on escalating stakes, evolving relationships, and the harsh cost of survival.

Underworld - The Succubi: A LitRPG Series by Apollos Thorne follows Elorion as he reaches the succubi capital and confronts everything he thought he knew about demons, magic, and the Underworld’s politics. As war looms, the true nature of Lilith’s long-running human experiment comes to light, forcing Elorion and Aeris to navigate dangerous alliances and hidden agendas. Blending virtual reality game mechanics with dark fantasy, harem elements, and progression-focused power growth, the story pushes its young protagonists into direct conflict with the most influential forces in this demonic realm. The novel continues the series’ mix of adventure, romance, and horror within a game-like world where every choice carries escalating consequences.