Zul Ashur has two abilities, one is a solid ward effect, one that forces your opponent to lose two life if they want to target her with a spell or ability, which isn't too bad but pretty easy to work around
Archon of Emeria Rule of Law effects can be powerful
Do I think that means the Vault has more upside than the Crypt
As a result there is some ambiguity in their behavior, which are partly defined by the rulings issued for Mystery Booster : Unlike a normal token, a token card doesnt cease to exist in a zone other than the battlefield
However, it means you'll probably have to deal with international shipping in order to get your hands on it.
This card would need some outstanding Metal-type support to see success in this format so if you love this card, you really need to hope for that