Theory:Doctor Who television discontinuity and plot holes/The Halloween Apocalypse

The Lupari
"The Lupari are species-bonded with humanity, meaning each human had a Lupar to protect them".

So, there are multiple reasons as to how this premise makes absolutely no sense, but I'll start with the biggest and most obvious: how is this the first time we're hearing of this? Why has literally no other human in the history of the DWU had a Lupari show up to intervene in their lives?


 * Most Doctor Who stories on Earth are so small scale that its not implausible the Lupari didn't hear about them and the bigger invasions take place so quickly that they likely don't have an opportunity to intervene. Furthermore this whole species bond could just be a specific response to the universal threat of the Flux, with more powerful races being assigned less advanced species to rescue.

The Sun
The method of protecting Earth from the Flux was to cover all of the Lupari ships over the entire circumference of the Earth. That's all well and good, but what about the Sun? If the Sun is destroyed by the Flux, Earth is still doomed.