Electrgon, being upset at the demise of its creations by Dravolent, attacked Dravolent immediately upon their encounter. The two, both being immortal, fought without cease for what seemed to be eternity. The war sparked the creation of Kyogre and Groudon (and thus the canon war between them), and threatened to destroy everything until the beginning of the Opposed Phase.
Eventually human civilization was able to develop to a point where groups large enough to form a resistance could form. One civilization, which would eventually become the main ethnic group in the Derukia and Sinnoh regions, had a group which colonized the area near Electrgon's point of origin, which by that point was already recognizable as Derukia Lake, albeit with a lower water level. This group manufactured a strange glowing scepter from the stones where Electrgon came into this dimension, and gave it to the first Pokémon Trainer- an enigmatic man with an Armair. Using this scepter, Electrgon and Dravolent were each sealed in their own sub-dimensions, where they could not harm each other or anything else.
In 's region, mythology tells of a mythical ancient war between and . This war lasted 1000 years, hence the name, and resulted in many and constant casualties up until its end.