Pokémon Conquest

Pokémon Conquest (ポケモン＋ノブナガの野望 Pokemon Purasu Nobunaga no Yabō?, also known in Japan as Pokémon + Nobunaga's Ambition) is a role-playing strategy video game for Pokémon games and Nobunaga's Ambition games for the Nintendo DS. It was released in Japan on March 17 2012, and in North America on June 21 2012.

Story
There was a legend that was foretold that whoever unifies all 17 kingdoms of the Ransei Region will have a chance to encounter the Legendary Pokémon who created the region. Since then, Warriors and Warlords all over the region have sought to fulfill this foretold legend by attacking other kingdoms, thus bringing Ransei's peacful era to an end.