I'm looking for the title of a book my mother read to me when I was young. I am sure it was a book, not 100% though as I was 8-11, around 15 years ago. MAybe a short? This was 1998-2002 or so, so not a new story but not sure when the book was published. The following details may be a little spotty, any input would be greatly appreciated.
I remember this story including a main character and a rival of his. I do not remember if they were human or alien, though most probably the latter. The two were rivals, possibly it was a confrontation that caused them to be enemies instead, but they had reason to wage battles, the 'rival' being the instigator in most or all cases, the instigator, if I remember correctly.
These beings were form transferable entities similar to mind uploading or transference but their tale stretches farther than simply transferring being to a simple animal. They may have started basic, of which I have no memory of, but what I do remember is their consciousness being able to transfer first to a spaceship or starship and battled each other this way, then the main character actually transferred his consciousness to a planet (I think I remember that) and is then MAYBE attacked by the rival, still as a starship? Unfortunately, I have no memory of an ending or conclusion, but this has been driving me crazy for years.
The story may have involved other characters, but not that I can remember much of so possibly they did not play much of a part or have much effect in the story. I do not remember the process of their ability to transfer their mind to other objects but do not think it was technology based like plugging into a mind transfer computer. Maybe they were multidimensional beings, possibly without any natural form of their own but could live within objects of their choosing? If they were human, possibly it was an ability gained from going through a wormhole or collapsing star(?)