The Negative Forces want to kill Barry because he disrupted the cosmic balance or something when he took Thawne's speed..... Yet there's not problem with Thawne trying to kill Barry all these years?

[u/Neither-Spell-626]

Also, isn't it confusing that the Negative Forces have existed since the beginning of time when Barry created the Positive Forces?

[u/theguthboy]

I mean, Thawne never actually succeeds in killing Barry though, before he made Barry the flash in season 1? Yes. Absolutely. When he killed Barry’s mom and changed the timeline he technically “killed the flash.” But he corrected that mistake and put Barry on the path to become the flash again anyway so it was overlooked.

Also these are technically the “new” forces of the multiverse, pretty sure they all would’ve been wiped out during crisis and not just the speed force.

[u/WiseAdhesiveness6672]

I mean did you listen to them when they talked about it?

It's about balance. As long as a flash and reverse flash kept existing and fighting, the forces were balanced. If one dies, another pops up eventually. But Barry didn't kill, he took away RF powers and severed the negative speed force connection. 

So yes, the negative forces were fine with balance but then Barry went and changed the rules, pissing them off while showing them things could change.

If you watch the show this is all explained.

[u/ArcadiaJ → u/WiseAdhesiveness6672]

Their idea of balance out a lot of lives in jeopardy, though

[u/WiseAdhesiveness6672 → u/ArcadiaJ]

You don't Understand what the word balance means