Mister-Orion
(Friendly heads-up. This book uses characters created by friends, so in sense this a fanfic.)
Three close friends, Luke, a Garchomp, Phil, a Gallade and Morgan, an Umbreon, are about to have their lives turned around somewhat drastically when they stumble across a Gem that has the ability to increase the power of certain types of Pokémon to a surprising level. Because of this godly effect, the three decide to travel and find out what the Gem is and whether or not they can sell it to someone in order to obtain the finances needed to rebuild Firesky, a village that has been basically home to them.
During their adventure, the friends discover that the Gem is not just some odd stone, but is part of something much, much more than what they could ever expect, as they stumble across groups locked in conflict; desperately searching for these power-enhancing stones. Rumours spread quickly about the Gems are made by God itself, Arceus.
Learning of this, the friends are forced to join a war that of which they no nothing about, nor the goals of the sides at play. Because of this involuntary decision, they must take the word of the group forcing them to fight - that being that the whole nation and possibly world is in extreme danger, as a bunch of fanatics aim to gather these Gems as offerings to their Leader.
Reluctantly, they fight, given the simple choice to either do so, or face execution for treason.