Ash and the Last Armarouge

Long before Aura Guardians were well-known, they usually had a choice in partners: the attacker, Lucario, or the speedster, Greninja. But, there was a third that was preferred over most for a time: Armarouge, the Fire Warrior Pokemon. As the embodiment of defensive maneuvers, these Aura Pokemon utilize their Aura for protection, rather than offensive or seeking purposes. 500 years ago, that changed when the last Armarouge died of injury, burying their legacy for 5 centuries. Until one grateful Charcadet stumbles across Ash and Goh admiring the Auspicious Armor in question.

Note: I did not watch the actual series, so any accounts of the Goh are purely based off of research.