Barry screwed himself over in some pretty immediate ways in the Season 3 premiere, and he’ll evidently continue to feel the effects thanks to how his actions affected Clariss in this new modified timeline.
It looks like the big breaks in Clariss’ personalities have been directly connected to Barry messing with the timeline.
Interestingly, it appears that Barry will only have himself to blame for this new baddie.
Barry essentially created his future foe, and only time will tell if he’ll be able to pick up the pieces without monumental collateral damage.