Well, as Lucrezia says, she has killed many queens. At least we assume she is the reason behind their demise. Or an assassin taking advantage of situations of “flame on the ebb” like she says here about Anglia. Reason behind that maybe something else (perhaps something for our gang to investigate) but it seems likely she has, or has had, access to weaponry that is fatal to the Queens. This is of course the clank body and is hopefully still cut off from the other versions of her (I assume there is an original one in wherever the mind implantation engine connects to) but I very much hope Agatha’s idea works, and quick!