is Dr Who cannon here? if it is how would the Darlek react to the decepticons. would the two groups find themseves agaisnt eachother like darlek and cybermen or would they have a reclucance truce
Dr Who is here. But time travel is... finnicky.
Like said a good 40~ish pages ago, there are only a couple of beings that are making sure that time remains stable. One of these is Majora from "Majora's Mask", and even they need help from their enemy/maybe-BF Link to make sure that everything runs smoothly (it's 3DS Majora; they noticed that something changed with reality, and after enough repeats of the Terminian Cycle they.... mellowed out. The strange power of "artistic creative liberties", everyone.) . Another group is the "Golden Sun" cast/setting. Or the Aztec Deity of Time.
Sure, the Doctor can still use the Tardis, but it is contained only to places that are visited in HIS Show. And even then, even if he tried to derail things, it wouldn't work.
The moment something - or someone - tries to change the past, that change is ignored entirely in the Main Timeline - as if the time travel never happened - , and the "changed timeline" becomes it's own separate 5hing.
There is only ONE (1) Main Timeline: if anyone tried to, say, go back to when the Merge happened - in order to undo/stop the incident that triggered it - , then That Change would exist. But only in it's own timeline.
Does that make any sense? Even if you are sucessfull, the moment you travel to the past you are already diverting the timeline.
As for "Back to the Future" - which faces similar issues -, the changes done to That Past are actually Intended, so we would have some Left-ov3rs. But, theoretically, everytime the protagonists leave a time-period/timeline in order to get back to their time, that timeline/time-period xontinues to exist in its own separate path
TLDR: Time Travel is tricky. I tried to explain it as best as I could.
But don't worry, there's no risk of someone becoming "unborn" because a time-traveling prick killed off A version of their child-selves. Heck, even if The Doctor tried to kill his earliest Self, that still wouldn't erase them from reality.