ok this speculation is probably wrong, but could seem kinda spoilerish, so be warned.
I think tom is the missing lord demons son, with rupert being his little brother. after not dieing in the explosion toms father was pulled back and bound as the first , or one of the first demons. as time manipulation is potentially part of this series. would explain why Rupert looks like Tom , and why hes a class 4 demon. Of course he could really be tom’s son, they due have ftl equipment that no one knows really how to use, tachyons and all.
Saying all this I’m just trying to read between the lines I have read library’s worth of fiction and don’t know the author beyond living in his head through his works
Signed, Oryn Starheart
Demon of Metals and Radiation