We don’t have a description for season 6 yet, but no doubt Eobard Thawne (the Reverse Flash) will have a pivotal role given his recent escape at the end of the last season.
The Flash has always been my favourite Arrowverse series, but recently the traditional episodic format is starting to show its age. They’ll have an overarching villain storyline that goes through the season, but not much happens until the second half, Tom Cavanagh continues to play half the roles, and most issues that crop up in episodes appear to be resolved incredibly quickly. For example; last season Barry and Iris looked like they were going to temporarily break up which brought some potentially exciting drama to their relationship, only for them to resolve everything by the episode’s end.
I’ve always loved the character of The Flash, and I adore Grant Gustin’s portrayal of him. It’s a brilliant show and I’m sure I’ll watch it right up until the series concludes, but man I wish they’d change up the formula a bit before it gets stale.