In PMD, I was thinking there could be special Type Orbs, one for each pokemon Type. Both Silence and the good teams could be trying to collect them, and the good teams end up with then all and head to the Darkness Temple, where the Darkness Seal is (and where Asuma first got the Darkness Mirrior). Surprisingly, the seal breaks from the Type Orbs, and Regigigas is freed. He has almost defeated the good teams, but the Type Orbs head to the main town (forgot its name) and other towns like Asuma's town and minor villages. There, the people cheer for the good team's success,restoring their power.