What we could have had:
TVD S1: Elena (unicorn/hunter), Bonnie (witch), Caroline (vampire), and Hayley (werewolf) [Jeremy, Enzo, Matt, and Tyler, too, I guess] are introduced to the supernatural. We should see their before, origin points, and foreshadowing what's to follow. This season sets the tone and the world rules for all future seasons by establishing lore, dread, and tension; bad things happen but we only see the suggestion of something-not-right. (Keyword: DREAD)
TVD S2: The Mystic Falls Girl Gang versus Katherine and her Salvatore brothers. Katherine, on the run from Klaus but still following his orders, torments Elena and her surviving family (Jeremy, Jenna, Alaric, John, and Isobel). Damon is really leaning into the Dracula thing by killing "his brides" and kills/turns Caroline and attacks Bonnie. Stefan is angsting over his latest binge-feeding and trying to play "human" but not human enough to save the Gang. Klaus should be suggested here. This season is a turning point and the terror of becoming and inevitability. Our monster girls should grow more monstrous, sacrificing their humanity for each other. (Keyword: TERROR)
TVD S3: The Mystic Falls Girl Gang versus the Mikaelsons. Supernatural royalty shows up for what they think is a power-up blood ritual, maybe unlocking their hybrid potential as a family. They were created because their parents feared their inevitable deaths so having the siblings driven to extreme action to escape their timely demise makes sense. (The nuance of obscenely powerful characters consumed and eventually defeated in their quest for more power because they're terrified is delicious.) Also, death to the sad bad boy justification—Klaus isn't a bastard or the only hybrid anymore. Mikael, a viking, had a wife (Dahlia (hunter), the mother of Elijah, Freya, and Finn), a frilla or mistress (Esther (werewolf), the mother of Niklaus and Rebekah), and a thrall or slave (Ayanna (witch), the mother of Kol and Henrik). The women hate Mikael but love their children and seek their immortality with Ayanna's magic and the unicorn's blood—however because they killed the unicorn the consequences are dire creating hunter/vampires, werewolf/vampires, and witch/vampires (siphons) that are more powerful than humans, hunters, werewolves, and vampires because the wlrldbuilding already supports this. Maybe after centuries of in-fighting, Klaus still daggers his siblings because he's still paranoid of any threat to his power—just imagine a defeated Klaus un-daggering Rebekah and Kol and having to admit he was bested by the Mystic Falls Homecoming court. (You're welcome.) Obviously, even with his siblings, the Gang runs them out of town and they flee to New Orleans with the agreement to stay west of the Mississippi River from then on. They still get theor spin-off where they face their parents and eventually reclaim their humanity/mortality. This season should end with the Mystic Falls Girl Gang becoming more monstrous than the monsters they were so against in the beginning amd the horrors they commit after shedding their humanity for each other. Yum. (Keyword: HORROR)
Then their story ends so I don't have to suffer through 8 seasons of bad writing from CW.