I liked the structure you were going for here, and seeing O5 drama SCPs is always a solid hook for me. Unfortunately, there were a couple of things that just kind of broke immersion for me. I'll be honest, I have a lot to say and most of it is negative. But please, if you read this, don't get discouraged!! Keep writing regardless!
The very top one being that there is no way that people as powerful as the O5 Council would allow two of their members to be married/separated/parents to the same child—basically because of something exactly like this happening. But even if they did allow such a thing, the moment one of them starts going after the other (the way 10 went after 8), the rest would pretty much immediately eject both sides when decision making started.
Additionally, the dialog felt remarkably childish for two people with the weight of O5 responsibilities on them. People curse, but the amount of cursing in some of 8's notes was enough to pull me out of the story—it didn't feel like he was frustrated, it just felt like a child who recently discovered he's allowed to curse. And the interview between 8 and 10, while believable in the context of some people chatting in the hallway, is entirely unbelievable in the context of a secure, recorded, and council-mandated interview. The complete lack of professionality that either of these two have while making up ~1/6 of the steering power of the entire SCP Foundation is concerning and unbelievable.
The idea of an entire trained Mobile Task Force being taken out by a single non-anomalous individual also seems incredibly unlikely to me, but it's something I would have let slide if I weren't already put in a critical mood by the previous suggestions.
Overall, within the context of the SCP universe, I think there are too many violations of logic to make this good. Had it been lower-level researchers I think I would have believed it more, but the fact it took place at the O5 level made the rest of this unbelievable for me.
Again, please don't let my remarks discourage you from writing more!