I find this logline a bit vague. At this moment, I don't think "tragedy, betrayal, and chaos" are the key to hook the audience. Instead, "What makes the seven old acquaintances reunite?" and "What was their relationship before?" will interest me more.

Therefore, I suggest something like this:

After many years, seven "RELATIONSHIP" friends are forced to reunite when a mysterious adversary threatens to reveal their darkest secrets and destroy all they hold dear.

I hope it helps.

I agree with Sam Iwata Aka Liu it does feel a bit vague.