In Fire Emblem: Genealogy of the Holy War, little is mentioned about the Deadlords, but they are all fought in the Final Chapter near Barhara and eventually defeated, including Draco himself.
Draco should be relatively easy to defeat. As he is a Sniper, simply corner him by surrounding him on all four sides before attacking. This might not be absolutely necessary, considering his abysmal defenses.
Draco may not be able to directly attack, but it is not advisable to let your guard down. She is able to dodge extremely well, and the presence of the Prayer skill only makes her all the more deadly. First off, ensure that Mus has been killed, so that his leadership stars will not increase the difficulty of taking Draco down. Secondly, if Ced or Galzus is nearby her, they should be able to defeat her fairly easily, assuming that her prayer skill does not activate. However, if Mareeta is close by her, she will be able to wreck havoc upon Draco easily with Mareeta's Sword, due to the fact that said sword grants her the Awareness skill, essentially nullifying Prayer. However, the player may want Mareeta to take care of Canis instead. If all else fails, simply use a Sleep Staff on Draco to prevent her from retaliating during attacks.
Fünf, Draco's Japanese name, is a German number, which, in this case, means 'five'.
In the English version, the Deadlords' names are based off the Latin names of the animals of the Chinese Zodiac. "Draco" means "dragon", the fifth animal of the Chinese Zodiac.