They make Harrison worse every year. The show has been boring at times, but I appreciate the tone the series has. But as usual they get too silly with it. I see them bringing in Thawne somehow. I wouldn't mind seeing Thawne disguised as Wells come back and take on the Wells role somehow. Maybe have him reform, and he just wears Wells as a disguise and out of familiarity with the team. He eventually returns to evil for the last season.
That'd be cool I keep thinking Thawne will be the villain of the final season. What if during his time fighting the legends he arranged to save himself by having Eddie somehow have his death and his erasure from time faked. He has been secretly grooming Eddie all these years. At some point he gives Eddie speed powers, and he uses the Black Flash powers to resurrect Zoom, Rival and Savitar. The final episode is Barry, Wally, Jessie, Jay and Xs vs The Thawnes, Zoom, Rival and Savitar.
But in addition the Rogues will have a war with Team Flash including Ronnie who somehow returns and becomes Firestorm with Jax. Perhaps Snart didn't die when at the end of Legends season 1 and he Ronnie were both shunted to the same dimension, and they get rescued by Flash. They help defeat the Rogues.
It ends with Barry finally defeating Thawne, and retiring from crime fighting because Iris is pregnant. Wally becomes the Flash, and Ronnie and Caitlyn leave Central City. Snart becomes Citizen Cold and works with Team Flash. It ends with Wally persuing a white suit speedster named Godspeed while Eddie watches from a cell on tv with lightning flashing in his eyes.