As the king of Renais, he had a fair relationship with Vigarde, until Grado suddenly attacked Renais without warning. Grado's forces quickly overwhelmed the unprepared Renais soldiers and eventually reached the castle. Before the castle was besieged, Fado entrusted Seth to take Eirika to safety. Although it is unknown what happened after Seth left with Eirika, it is very likely that Fado was killed as he is never seen again.
In the Creature Campaign, you can acquire him as a Level 11 General if you clear the Lagdou Ruins in its entirety once.