It is unclear how Thorn, Murtagh's dragon, matured to rival Saphira despite their age difference, but Christopher Paolini has stated that it will be revealed in the third book of the trilogy.
The nature of the spirits that sorcerers summon will be revealed; already it has been stated that they are not the souls of sentient creatures returned from the afterlife.
瓦登=維登(The Varden)
娜蘇艾達=娜紗妲(Nasuada)
鮑里尼=鮑里尼(Paolini)
薩菲拉=思飛(Saphira)