Space Pirate Charlie: The Dragon Mage Book 2

Charlie, a spaceman from Earth, found himself transported to a distant galaxy and has survived a surprising amount of trouble, including space pirates and a dragon. Now, he's living a life of unexpected luxury on a powerful wizard's estate after being a gladiator slave.

But this captive comfort on a strange world is far from ideal. As he struggles with the lack of freedom, Charlie suspects something is amiss. Even a gilded cage is still a cage.

Having learned to fight, use magic, and kill to survive, he wonders how long his cushy existence will last. He soon gets his answer: not long at all.