Is Titans season 3 finally picking up an old Jason Todd storyline that was abandoned under mysterious circumstances? Towards the end of Titans season 1, Raven's demonic father, Trigon, emerged from his inter-dimensional prison and began corrupting the universe, starting with his daughter. Trapped in Trigon's darkness, Raven uses her powers to psychically contact a comatose Dawn. Titans season 1's "Hank & Dawn" episode ends with Dove regaining consciousness and claiming Raven "reached out" with a message to find Jason Todd. When Curran Walters' character arrives on the scene, however, he's just as useless as the other Titans. The day is eventually saved by Beast Boy, who talks Raven around so she can defeat her father.
Titans has never properly addressed why Jason Todd was deemed so important, nor why Raven made Hank and Dawn fetch him, and this is likely due to huge changes implemented between Titans seasons 1 & 2. According to various reports and leaks, the original Titans season 1 finale featured a totally different ending to the Trigon battle, which even included the Doom Patrol coming to lend a hand. This ditched episode might've addressed the need for Jason Todd's presence, but in the version that aired, Jason's biggest contribution is screaming "Titans are back bitches!" down the lens of a news camera.
Unexpectedly, it seems Titans season 3 might be revisiting that story. In the season's fifth episode, "Lazarus," a flashback reveals what happened to Jason Todd between Titans seasons 2 & 3, after his return to Gotham City but before becoming Red Hood. Sleeping in his Wayne Manor bedroom, Jason suffers a nightmare where Donna Troy (who died in Titans' season 2 finale) appears and says "don't go... you still have time Jason."
This strange scene generates a number of pressing questions. First off, what does Jason still have time for? To turn his life around? To get over his fear complex? To watch adult videos on the Bat computer? More pressingly, why is Jason dreaming about Donna at all? Though the pair worked together (briefly) in the Titans, there was no special connection. Jason wasn't present for Donna Troy's death either, so there's no reason he'd feel guilty or be traumatized by the incident. Though the dream sequence is undoubtedly odd, Titans might be picking up the aforementioned "Jason Todd is special" storyline that season 1 left dangling.
Everything started with Raven. She was the one who subconsciously contacted Dawn and told her Jason Todd was important. But Raven never said when he'd become important, and still doesn't fully understand her powers. Rachel Roth certainly has no control over her precognition, so can't shed any light on her Jason Todd prophecy from season 1. It's possible, therefore, that whatever the Titans needed Jason for hasn't happened yet. Dawn and the gang mistakenly believed Batman's second Robin would be vital against Trigon, but Raven could've been foreshadowing an event further into the future. This would also explain why Jason sees Donna in his season 3 dream sequence. Raven is currently using her demonic abilities to resurrect Donna on Themyscira, so her power is connected to Wonder Girl's spirit. This "you still have time" message might be coming from Raven, but through Donna because the two are currently connected.
Addressing Dawn's dream and Jason Todd's importance would be a great move for Titans season 3. Most fans concur that the DC series has improved over time, and revisiting glaring plot holes rewards fans who stuck around long enough to see Titans find its feet. As for why Raven keeps insisting Jason is important, there must be a future villain only he can defeat. Perhaps someone who sees him as a surrogate son and recently went rogue...