The sixth season of The 100 has provided an ambitious new direction for the post-apocalyptic series as the main cast has traveled from a devastated Earth to the distant world of Sanctum. Upon their arrival, they discovered a planet with its own lethal dangers, settled by an earlier expedition from Earth, and presided over by a ruling class known as the Primes, revered by the populace as living gods.

The main characters quickly found themselves at odds with the Primes after learning the rulers had rendered themselves virtually immortal by transferring their consciousnesses into new host bodies for generations, and planned to do the same with the new arrivals. With Tuesday's Season 6 finale promising an epic final confrontation with the Primes for the fate of Sanctum, here are the most likely main characters to die by the episode's end.

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Russell Lightbourne: 87%

The leader of the Primes, Russell Lightbourne has served as the principal antagonist this season. Currently occupying his sixth host body, Russell has been conflicted about the fate of his people since meeting the new arrivals from Earth, but deems their presence necessary, as compatible host bodies dwindled on Sanctum.

As the season progressed, Russell lost many of his fellow Primes, including his wife and daughter, further hardening his resolve and leading him to take desperate measures. The penultimate episode marked a full heel turn as he deliberately plunged his people into violent chaos to make his escape in a bid to seize control of the spaceship the Eligius IV, where he is likely to meet his end.

Abby Griffin/Simone Lightbourne: 64%

Technically speaking, Abby Griffin, mother of main protagonist Clarke and a major presence since the pilot, was already killed in the penultimate episode of Season 6. Used as a host body for Russell's wife Simone Lightbourne, the last traces of Abby Griffin were eradicated to make way for the devious rebirth of the new consciousness.

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Joining Russell in his attempt to take control of the Eligius IV, Simone will provide a painful, visual reminder to Abby's friends and family, and what they have lost since arriving on Sanctum. And with Clarke secretly in tow, she may spare Simone, as killing her mother's old body may be too painful. However, that mercy is hardly a guarantee.

Echo/Ash: 56%

Season 6 has been especially revelatory for Echo, whose past had been largely kept under wraps since her debut in Season 2. Progressing from antagonistic ally to a firm friend and love interest to main character Bellamy Blake, Echo confronted her troubled history on Sanctum, eventually revealing that the rest of her family had been lost in a fire. She later disclosed she wasn't originally named Echo at all, but Ash, and was forced to take on the new identity after killing her best friend on Earth.

Bringing so much of Echo's backstory to light seems like a way to set up her death, which would also serve as a convenient means to establish the long-simmering romance between Bellamy and Clarke that has been hoped for by many fans.

Jordan Green: 32%

Poor Jordan Green. The adult son of former main characters Monty and Harper was placed into cyrosleep by his parents so he could join their friends to start a new life on Sanctum, even as they died of old age to ensure the Eligius IV would reach Sanctum safely. Since emerging to learn of his parents' death, Jordan found love with a Sanctum resident named Delilah, only for her consciousness to be destroyed when her body was possessed by the Prime Priya.

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After learning of Delilah's fate, Jordan's behavior grew more erratic, resulting in him saving Simone from an out-of-control Madi Griffin. The rescue was not without its own cost, however, as Madi accidentally grievously wounded Jordan, who has been largely incapacitated ever since. While Jordan's health is questionable going into the finale, it is unlikely such a relatively new main character would die, but certainly not impossible.

Madi Griffin: 14%

Speaking of Madi, the adopted daughter of Clarke has had a particularly rough experience for much of Season 6. A mind drive containing many of the past leaders from one of Earth's surviving clans was implanted in Madi, and Clarke helped her daughter to manage the multiple personalities within it. However, as Clarke has been preoccupied with regaining control of her own body from the Prime Josephine Lightbourne, Madi has fallen under the influence of a malevolent persona known as the Dark Commander.

That dark personality, coupled with Madi's desire to avenge Clarke after believing her lost to Josephine, led the girl to cut a bloody path against the Primes before being subdued and imprisoned. Madi is severely weakened from blood loss, as her bone marrow was harvested to make additional compatible hosts, but no less lethal. While Madi is worse for wear and still a prisoner of the Primes, Clarke's daughter is likely safe, as killing a child may be too off-putting for the finale.

Gaia: 49%

Gaia has served as Madi's loyal protector, and attempted to keep her violent outbursts in check this season during Clarke's struggles. However, that has also placed Gaia as a prisoner to the Primes in order to remain close to Madi as the conflict inevitably escalated.

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Because Madi believes her mother and grandmother have been lost to the Primes, Gaia's potential murder at their hands may be the last factor to send the girl over the edge and make the Dark Commander's influence complete.

Emori: 51%

Emori has questioned allegiances for much of Season 6 after her longtime boyfriend John Murphy sided with the Primes in effort to gain immortality for himself and her. Since then, Emori allied with her friends in their efforts to rescue Clarke from Josephine while maintaining her love for Murphy and staying by his side.

The penultimate episode of Season 6 confirmed Murphy and Emori were both now actively against the Primes after learning that Clarke was successful in destroying Josephine. However, as Sanctum's general populace has descended into a toxin-induced madness, Murphy and Emori have both decided to set out and rescue their friends from the bloody chaos. While Murphy himself will likely escape death, his girlfriend may pay the ultimate price.

The 100 airs on The CW Tuesdays at 9 p.m. ET/PT. The series stars Eliza Taylor, Paige Turco, Marie Avgeropoulos, Bob Morley, Henry Ian Cusick, Lindsey Morgan, Richard Harmon and Tasya Teles.