But in preiviews he believes that altering one thing will change the outcome. He doesn't need to change everything just one thing. And that is the one thing that they inadvertently change without knowing that was also part of the future. The thing that's still a mystery is how Savitar got his box and escaped the speed force. Someone likely went and fetched it for him but who and why. Could it be Wally, Jay Barry or even the reverse flash. This is why I don't think killer frost is the one who betrays the team. The betrayal has to be reuniting Savitar with his box. So I think speedster would have to do that

Another way of looking at it is that because Barry doesn't know about it, he doesn't take any steps to prevent it from happening.

I wonder if that's thats the one thing from the future they might be able to change. I don't think Barry saw bit about killer frost so that may be the one thing they could change without being aware that they actually changed it. And that's the one thing that could alter the future timeline.
I noticed in the prieviews someone is missing and that's Joe so I wonder if he's being kept in the dark about what will happen to Iris

Hopefully it is true. The Killer Frost storyline has been handled horribly so far and while I think it is obvious they will have Caitlin turn back good in time for the following season I would like to see her go all out as a villain and cause a lot of damage and kill innocent people like Dark Willow in Season 6 of Buffy.

The catacombs
And revolving doors inside of my brain
Preachers and whores
And the neon pulpits burst into flames
I come from both
Sides of me and either side of their tracks
Humbling my ghosts
Letting life that floods my veins bring me back
The unshackling of the chains on my wrists
And the loyalty to pain that resists
And the greatest books are talking about this
Why must everybody die to exist?

This feels like some kind of setup where Team Flash set this all up to trick Savitar. The ironic thing is that it's probably because of Barry seeing the future that will cause it to happen, a paradox.

Harvey Dent was loved, that didn't stop him from becoming Two-Face. Get real.

I do not see it happening, she is a character loved by the public and many do not want to see her becoming a villain.
Perhaps with her powers she becomes more concerned with herself and wants to fight for herself to help others, but her personality, her essence will always prevail.

I want her to be evil, it creates good drama in the story.

Or it could be Grodd mind controlling both of them.

For me, that's red herring, it's for us to think she'll do bad things, but it's actually something else.
Caitlin will struggle with her powers, but she will commit something there or here (nothing too serious), but that is enough that when something seriously bad happens and she may be involved, she is considered guilty.
From that vision of Cisco I have it in my head:
And her fight with Cisco for me is one of three things:

• Cisco will somehow be controlled by someone and attack Caitlin and she will try to defend herself, but without hurting him.
• is some metahuman with powers to turn into anyone (and replicate powers) that will take the form of Cisco to attack Caitlin.
• will be a memory implanted in the mind of Cisco and Caitlin (or of the two), to put them against each other.

I am with you on that. But I still hope she doesn't