Looks like the original story in the game got reversed? (like how these seven heroes became the main villain in the story, and the villain from the game became hero?) or the whole story in the game was a misunderstanding plot (like this great noble Ignart's daughter died in the game because of the seven heroes?, and he did the revenge for it, that's why the "players" in the game classified him as the last boss/main villain). Also, in the MC's dream, where he saw Len carrying Lycia's dead body, probably someone took the magic stone/demon stone inside Lycia's body, and Len saw it; which is why from the MC's perspective, Len had this raging/killing aura, and the MC mistook it as Lycia was killed by Len.