I couldn't miss the chance to practice my drawing!
The Templar, Moogle Knight, and Alchemist classes can give units the Astra status. Al-Cid Margrace, as an Agent, can also give a female unit Astra with the Reception ability. Astra can also be granted to units by the Shield of Steel Opportunity Command, which affects the user and the three ally surrounding it.
Astra not only prevents targets from being inflicted with the Doom status, but targets that are already inflicted with Doom can be saved by Astra if Astra is used before the countdown reaches zero.
While the status does not have a specific name, some Soul Breaks bestow a barrier that protects against Poison, Silence, Paralyze, Confuse, Slow, Stop, Blind, Sleep, Petrify, Berserk, Sap, Stun, and Frozen. If an enemy's attack would inflict any number of these status effects, the status effect(s) will not be applied and the barrier will be removed.
Astra means "stars" in Latin.