Testarossa/Chronology

Hero Awakening Arc
She was recruited by Diablo who was looking for subordinates to help out with chores. At first, Rimuru thought she wasn't strong but Raphael quickly corrected him. She was excited to meet Rimuru and hoped he would accept her. After changing locations the unnamed Testarossa gained a physical body by fusing together with an Emulated Soul and inhabiting one of the many bodies in the growth capsules prepared by Rimuru. Fitting for their status, all 3 Primordials' skeleton has gold mixed in and turned into Orichalcum, further improving the performance. After she gained the body, Rimuru named her along with 2 of her servants and 200 soldiers. The 2 servants were named Cien and Moss. Testarossa and Moss evolved into Demon peers from being named while Cien had his magicule limit as an Arch Demon released.

A bit later Testarossa was assigned with being the Military Attaché, a representative for the Council of the West. Testarossa accepted it with a gentle smile promising there would be no problems.

While Rimuru was in Ruberios, a Western States Council meeting took place. The meeting was in a huge crisis due to the main defense force of the Sidel border region disappearing. The demons from Guy's territory could easily run down Ingrassia like this. The emergency force to defend the country would be handled by Testarossa which was an unanimous decision but there were still complaints. Testarossa calmed everyone and asked Moss to report the situation to everyone in the meeting. After this the council members begun arguing which Testarossa listened to quietly. During this she eavesdropped on Johann Rosteia, the duke of the Rosteia Kingdom, who was using Magic Communication to give orders to disrupt the barrier around the city. She confronted Johann but was interrupted by the Apostles of Vert who summoned the Green Primordial, Misery. After Misery arrived she confronted Testarossa but in the end retreated and said she would fight Testarossa the next time they meet. With this everyone in the council learned Testarossa's true identity as the White Primordial but she also conquered the Western States Council and became highly influential in it.

Eve of War Arc
To Be Added.