Quote from Havrekjex »Since it only has flavor text, it doesn´t do anything by itself, which means that what it does and how you get it is solely dictated by cards that refer to it.Quote from SaprazZANY »Guesses as to what the city's blessing will do? Some kind of monarch-esque effect, maybe? It would be on-flavour for the Immortal Sun.
I expect a variety of cards that do normal things, and in addition to that have lines like:
"You get the City's Blessing"
"If you have the City's Blessing, draw a card"
"If you have the City's Blessing, this creature gets +1/+1"
"This creature can't attack unless you have the City's Blessing"
"If your opponent has the City's Blessing, you lose two life"
"If your opponent has the City's Blessing, he or she discards a card"
"If you have the City's Blessing, you lose it"
For flavour reasons I expect that you won´t be able to have more than one, so effects don´t stack. I can also see that some tribes/factions/colors are pro-Blessing and some are anti-Blessing, such as maybe white creatures give you the blessing and grant you bonuses for having it, while black reward you to not have it and possibly punishes your opponent for having it.
Monarch was taken from a mechanic in Ixalan that worked like this. It seems likely the city's blessing was developed on from that somehow.
Edit: No spoilers until January 1? I think it´s disappointing that they´re not going to do spoilers over the holiday. I always love it when they do that.
The 'previews' begin January 1st, but I think that means the official preview weeks, we may get a few more sneak peek cards between now and then. After all, we already have.