Can I use Eldegoss' "Breezy Gift" attack if I have no cards left in my deck?
Sure. You may not have any cards in your deck when you play it, but you will once you shuffle the Eldegoss and all attached cards into it.
Source: Stellar Crown FAQ; TPCi Rules Team (2024-09-12)

Relevant cards

Note: All applicable cards may not be listed below.
SV7_11
SV7_11