Choosing what rating to give this book took me thirty minutes and I'm still not sure what it should be. Why? Because it's a wonderfully piled heap of what the actual frick.
Definitely a product of its time, this book is very sexist, very shallow, the main character is a Gary Stu crossed with Jesus at Christianity purity levels over 9000 - he is "mega ultra smart" at like 10yo and already has a god complex by 17.
It has it all. A shopping list of all the things old fantasy books used to bring and they all run rampant! The whole thing was fascinating, hilarious and baffling usually all at the same time. Like this cute little snippet, (Kieron witnesses his FIL get killed, basically in his arms) "Well, then," Said Kieron, standing up.
It speeds through normal human emotions randomly, and then drags out others. It spends half the book telling us about how amazing-super-awesomesauce Kieron is, then BAM, plot changes to an old school revenge-adventure. This was a rollercoaster indeed! I love and hate this book, and many times realized that this might be the reason why fantasy/sci-fi tends to have a stigma around it - especially the older works.
Would I recommend this? No clue.