Chancellor of Niflheim. Ardyn rose to power by introducing Magitek infantry to the ranks of the imperial army and has since amassed political power at the emperor’s side. An aloof manner shrouds the chancellor in mystery.
“The man who was to be the first king of Lucis. Assuming the burden of the Starscourge borne by his subjects corrupted the Chosen’s body, causing the Crystal to deny his ascendance to the throne. Ardyn’s impurities grant him eternal life, which he spends plotting his revenge upon the blood royal and the True King.”
Ardyn Izunia is the Imperial Chancellor of Niflheim. He’s also the firstborn of the Izunia family and was to be the first Lucian king.
So when did Spiritus call Ardyn to World B? The most likely scenario is during the Starscourge and as he watches the Crystal absorb Noctis.