Auspicious Armor & Malicious Armor are exclusive evolution items that transform Charcadet into Armarouge or Ceruledge respectively. This evolution grants immense power to this Pokemon ensuring easy victories against foes.
Note: The Scarlet version holds Auspicious Armor in the trade whereas Violet holds Malicious Armor.
How to find Auspicious Armor (Armarouge)
Finding Auspicious Armor is a straightforward task, you just have to travel to Zapapico and trade with an NPC wearing a purple check shirt, standing in the center of the city beside the fountain.
The trade will require 10x Bronzor Fragments that can simply be farmed by defeating Bronzors at the ruins of West Province (Area One) or South Province (Area Three). Once you have the required fragments interact with the NPC again to get your hands on the Auspicious Armor and evolve your Charcadet into Armarouge.
How to find Malicious Armor (Ceruledge)
The NPC that trades this armor can be located at the same exact location (Zapapico) as the one who trades Auspicious Armor but this time it is a female who offers it.
This trade will require 10x Sinistea Chips. Hunt down Wild Sinisteas found on the eastern side of South Province (Area Six) and collect the required chips to trade the set of Malicious Armor, ultimately transforming Charcadet into Ceruledge.