Astral Mark of Bahamut FFXV (NGtE)

You passed the trial and now bear the Astral Mark of the Draconian Bahamut.

• You can summon the Draconian Bahamut to intervene in a time of need. If one or more of your allies are unconscious in an encounter with a Legendary creature, as an Action you can roll a d100, on an even number, Bahamut appears, an ethereal presence of an Astral entity. You can cast mordenkainen's sword and blade barrier simultaneously, using your Spell Save DC. The blade barrier does not require concentration and lasts for the duration unless dispelled or dismissed by you.
• If any Astral entity intervenes, you can’t use another Astral Mark feature again for 7 days. Otherwise, you can attempt to use it again after you finish a long rest.