The last chapter of Flux was proven to be.. a massacre. I can't say it was not unexpected, during an event that involves the destruction of the entire Universe some victims are expected to happen. There were some good moments, too. Only some, but good - the rate of the episode was a medium one (it was not bad, but it was far from something extraordinary).
And Tecteum returns in Doctor's time briefly (only in this episode) and unexpectedly: as Division chief she is the person accountable for the appearance of the Flux and for trying (more or less successfully) to destroy the Universe. The moments the two women spend together are at least interesting (and almost shadow the rest of the action): the Timeless Child could have come from another Universe and Tecteum tries to get there after she smashed her original Universe. She has the Doctors memories and it's only a problem of time (almost a week, for us) until she is going to get them back.
It's the first time it's introduced a rogue Weeping angel, one that runs from his people and from the Time Lords' Division, and who is capable to do anything and to betray anyone in order to escape. It's the first time such angel has (or it claims it has) the entire history of this Division, and also the lost memories of the Doctor, but it's unlikely it's going to share them.