The Eternal Black Mark currently has one completed "story", which are referred to as "Seasons", with each one attempting to tell a different story.

HEAVY SPOILERS FOR THE ENTIRE STORYLINE OF THE ENTIRE UNIVERSE, READ AT YOUR OWN DISCRETION.

Eternal Black Mark Season 1: Grand Reset.

EBM:GR is the first season of Eternal Black Mark, it's set in the current age (2020), in our current world, in an unnamed city. We find ourselves in the shoes of someone called Moon, and how he becomes a marked one, and finds himself trapped in time loops that force him to save those who are close to him from a supposed fated death.

Eternal Black Mark Season 2: Metamorphosis.

EBM:M is the second season of Eternal Black Mark, happening ???? years before the events of Grand Reset. Metamorphosis follows a group of 8 characters as they experience the Faith Crisis, with Wishbringers creating severe changes to their contracts, and the eventual death of many Wishbringers.

Eternal Black Mark Season Null: Estrangement.

EBM:NE is the third season of Eternal Black Mark, unlike the previous two season, Season Null/Estrangement, is a collection of stories that follow either small groups of characters, or stories that focus in the experiences of a single character, most of these stories are in no way related to each other, and happen in different periods of time.

Eternal Black Mark: Acme Series.

EBM:AS is not a season, but an experimental AU of the previous seasons that explores marked ones who have reached the pinnacle of their powers, becoming extremely powerful creatures. This season is canon in a way where Acme Series exists in an universe where the events of EBM Grand Reset, Metamorphosis, and Estrangement happened, but it's not canon because most of the characters of the series would have been able to reach their level of power organically. (Basically it's me making busted OCs for the fun of it).