Looking at Fado, he is one of the better secret characters, although nowhere near Ismaire due to his low level of growth and relatively low base stats. He has good HP, strength and defense, and his resistance is decent, but his skill, speed and most notably his luck will be his undoing. Fado's constitution is thankfully massive, so he can wield nearly any melee weapon without speed loss, and he comes with an A rank in all three weapon categories. His growths only really excel in HP, strength, defense and maybe skill, so only use Fado if you really want to. In case you needed it for any of your unpromoted Creature Campaign units, he comes with a Master Seal in his inventory, along with a Silver Axe, a Silver Sword, and a Silver Lance.
A 'fado' is a sad Portuguese folksong. The word comes from the Latin 'fatum' meaning 'fate.'
Also, "fadó" in Irish means "long ago".
In the cutscene he is featured in, his sprite is that of the unused Peer class also used in cutscenes by Elbert in Fire Emblem: Rekka no Ken. However, his sprite is changed to a General in the Creature Campaign.