Opening the Vault takes a while, so it's best to think about it as a "nice bonus" rather than a goal
It could be a bonus card randomly inserted into certain Secret Lairs (a la the Smothering Tithe from Spongebob drops), or maybe it's an add-on for spending a certain amount on the Secret Lair website, which shouldn't be that hard to do with these drops
What is the pull rate for Duskull
These packs are cheap, widely available, and usually include ten cards
Otherwise, you can combine Robin Hood, Daydreamer, with one of the new location cards featured in Into the Inklands to grant the character some additional protection from banishment - such as Pride Lands, Pride Rock, which gives an extra two health to any characters placed onto that location, or RLS Legacy, Solar Galleon, that will give the Evasive condition to any cards there: meaning that they cannot be challenged by any characters unless theyre also Evasive
The set includes multiple foil treatments such as elemental-pattern holo cards, Master Ball-pattern holo cards, and special gold-stamped foil cards featuring the Gem Pack logo