Looking for a book I read in the 90's (not sure if it was published in the 90's or not).
The story as far as I can remember goes like this. Human-looking aliens evolve on a very hostile planet. They encounter some big bad threat and they cast about for help. They encounter a rich industrialist on Earth and they send a woman to recruit him. She teaches the guy to use magic and how to transform his body. They build a ship and travel to her planet but just before they arrive, she vanishes and he crash lands on this hostile planet.
He goes through many trials and tribulations in order to get to her and eventually he has enough and uses the ability she teaches him on how to transform his body. He transforms himself into a half-man, half-dragon-like creature which allows him to travel to the other side of the planet to get to the girl. On the way he manages to neurally link into a large flying creature that flies very fast, only to discover that it is intelligent and they soon become friends. When he gets to the girl she doesn't recognise him so he gets mad and starts attacking only to realise that it's all been a test set up by these people to allow him to reach higher levels of magic.
There were supposed to be sequels but I never got around to reading them.
I remember the cover art depicted a large dragon like creature with a torso of a man and a woman standing in front of it looking back at him.
Any idea what this book may be?