Season nine of "Supernatural" ended with a cliffhanger that had Dean Winchester turning into a demon after he was stabbed to death by Metatron.

While fans of the CW series had expected either Sam or Dean to die in the finale, they were taken aback with the sudden twist. When Crowley forced open Dean's eyes, they were black, hinting that Dean has become the one thing that his family and friends have been trying to eradicate their entire lives.

If reactions on Twitter are any indication, fans of the CW series are sure what to make of the twist. While many feel it would be interesting to watch Dean as a demon, there are an equal number who are upset that he has lost his humanity, especially when the Winchester brothers were learning to appreciate each other.

A poignant reminder of their love for each other is the scene where Sam cries holding his brother's lifeless body. Although Sam tries to make a deal with Crowley, the current King of Hell, so as to bring back his brother, he fails to summon the demon.

"It's better this way. The mark is making me into something I don't want to be," Dean tells his brother before he dies, and adds that he is proud of them.

While nothing much is known about the next season, it will either focus on Dean accepting his new form, or follow Sam's attempts to restore Dean's humanity.

Meanwhile, the Supernatural boys told E!Online that they too were surprised by the finale's twist.

"It's my favorite finale we've ever done...True to Supernatural form, we go to the extreme...I mean we're 195 episodes in, we have to do something kind of big time. So we do. There will be a big audience reaction," Jared Padalecki, who plays Sam, told E!Online about the finale.

Jensen Ackles chimed in stating that he too was taken aback by the cliffhanger. "I know what my reaction was when I got to the end of the page and my mouth was open.I will say that this cliffhanger surprised me more than most."

Find below a few Twitter reactions to the season's finale episode of "Supernatural."