WARNING: The following contains major spoilers for The 100 Season 7, Episode 16, "The Last War," which aired Wednesday on The CW.

The 100 has come to an end after seven seasons, with humanity facing the ultimate test to determine if it is ready to transcend to the next stage of evolution. Greeting the individuals who enter the Anomaly Stone to represent the entire human race are familiar faces from their pasts, several of whom audiences hadn't seen for years after the respective characters died. And while the returning characters are avatars of a higher race judging humanity, the forms they take each come with a special significance to those they faced.

Bill Cadogan is the first individual to enter the Anomaly Stone, where he finds himself on a familiar pier where he used to take his daughter, Callie. While Callie perished on Earth centuries ago after leaving her father, Cadogan was reunited with a vision of her. The avatar describes herself as Cadogan's greatest teacher and the person he misses the most. Before Cadogan can represent humanity during the cosmic trial, however, he is shot and killed by Clarke Griffin, who is seeking revenge for all he cost her, including the loss of her daughter Madi.

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With Cadogan dead, Clarke now represents humanity in his place. The avatar shifts and takes the form of Lexa. Introduced during the second season, Lexa eventually became Clarke's lover while commanding the united Grounder tribes, as the Mind Drive containing all the digital consciousnesses of past Grounder leaders was implanted in her neck. Tragically killed during Season 3, Lexa was Clarke's greatest love and her death has haunted Clarke for the remainder of the series. Lexa finds humanity lacking at first, especially because Clarke is the first individual of any species that committed murder while taking the test.

Fortunately, Clarke isn't the only person to represent humanity during its cosmic test. Raven Reyes also enters the Anomaly Stone separate from Cadogan and Clarke, where she finds herself back on the Ark where she was born and grew up before coming to Earth. Raven sees a vision of Clarke's mother Abby who, in many ways, was a major antagonist to Raven during the series due to her drug dependency, which led to Raven's severe mistreatment and abuse at her hands.

Initially denying humanity's worthiness, the vision of Abby concedes to Raven after the two witness Octavia Blake convincing the Grounders and Disciples to stop fighting on Bardo, allowing Abby to see that humanity does not always have to rely on violence. Willing to take a chance on the human race, Abby deems the species worthy of transcending from their physical forms in a cosmic display of power.

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By enabling the return of fan-favorite actors to reprise their roles as these cosmic avatars, the finale provided audiences with a vision of the show's history while levying the ultimate judgment on the human race. Each reunion is bittersweet, yet each avatar provides greater insight into the three representatives of the human race as they enter the Anomaly Stone.

The 100 stars Eliza Taylor, Marie Avgeropoulos, Bob Morley, Lindsey Morgan, Richard Harmon, Tasya Teles, Shannon Kook and J.R. Bourne. The series airs on Wednesdays at 8 p.m. ET/PT on The CW.

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