Ascend unlocks different bonuses on different cards if you have the city's blessing. The city's blessing is a designation that the ascend ability can give you. The city's blessing isn't a permanent or emblem, and nothing can destroy it or otherwise interact with it.

If a creature you control explores, you reveal the top card of your library. If the revealed card is a land, representing your creature finding some new territory you can check out, put that card into your hand. If it's not a land card, your creature comes back empty-handed (or empty-winged, empty-taloned, empty-pawed, etc.) but still benefits from the attempt. Specifically, you put a +1/+1 counter on it. Then, you decide whether the nonland card goes back on top of your library or into your graveyard.