Please help, I have literally scoured the internet for information, can anyone identify?!
I read this book (these books, think it was part of a trilogy) when I was quite young, maybe 15 years ago now, and it may have already been around for a few. It may have had the words blood or portal in the title though I'm not sure.
I just remember that the human race (fairly primitive, swords and shields type era) had been enslaved by a race of gentically superior creatures (after numerous wars) called the csendrook (or something like that)
Various worlds of man were connected with portals that these creatures had invaded through (they were human-like but bigger, faster and with sharper teeth) The portals being opened using blood and littered with human skulls! No man had bested one of these creatures in battle for years, since the invasions, until a prince among men killed one. The rest of the story centres around his leading a rebellion I believe, leading to a sword confrontation with a prince of the csendrook (or whatever they are called) at the end. I believe the planet somehow mystically comes to the princes aid.
It probably sounds lame now, but I have very fond memories of this book, and if anyone could remember it I would be more than grateful!