The time-travelling trees and far-future Earth seen in this campaign segment were inspired by the book 'Hothouse', by Brian Aldiss. In this book (set in that far future) the characters run across a thing which seems to be 'transplanting' creatures to somewhere else. It was this which inspired the 'transplanter trees' plot.
The trees evolved time travel as a means of giving their seeds the best chance of survival; they are unaware of space but time is something they feel. At first a very minor (if useful) ability, they developed the power to swap areas about themselves with areas in the past. As they go, large seeds (their size partly to stop them being bothered by the wind) are fired up outside the radius of effect so that they fall into primitive vegetation that appears where the parent tree was, thus having a major advantage over anything already there.
A quirk of future geography meant this was only happening in Russia.
'Transplantation' warps local geomagnetic, gravitational and magic fields as it happens, which allows incoming 'transplants' to be detected before they occur, allowing things to be swapped into the future if desired. University geomagnetic and gravity wave sensors and experiments will pick up these effects and allow them to be triangulated (why there was activity at Moscow State University just before the start of part 2).
The trees have to store a lot of energy to travel through time. This takes them thousands of years of storing sunlight, and electricity from thunderstorms. This is why they are black, and also why the plant samples were such effective electricity stores - they are basically living capacitors. When they travel through time they use energy at the multiple nuclear bomb level; some of this is radiated away as waste at the ends of the time trip.
The sentient plants have bred the transplanter trees to make them more effective; they realise the Sun is dying and want to escape, but are also aware of space and the like, never having seen the stars due to the Earth of the future being tidally locked to the Sun.
As a race the sentient plants are slow and immobile, with some magic - generally for communications and summoning and control of local life forms. They do not want to die but they do not want to kill sentients if they can avoid it - they are entirely unaware that their past, where they are going - is inhabited.
The shield around the Earth in the far future was needed because the Sun's energy output apparently rises by 10% per billion years. Assuming the Earth's average temperature now is 285K (12 degrees Celsius) this means that :
So, by 500 million years into the future, someone realised that something would have to be done, or the Earth would, eventually, die...
The Viper-related part of the campaign segment was inspired by thoughts on the previous campaign segment - where the Chechen and Afghan superhumans got the information on the Sleeper.
The part of the plot relating to Sirdar's spirit being in Napalm's head grew out of thinking about Sirdar's powers and what they might imply. Napalm selling her soul to the Tibetans in return for his removal was unexpected, though!
Running this second Moscow Superheroes campaign segment has also given me third thoughts about turning my London Champions game into London Everway instead. Using the Everway system seems to have gone considerably better this time than it did in the first campaign segment...