FOILCheapest priced copy (The Lost Caverns of Ixalan Commander): $3.49 at Card Kingdom, near mint, their price list as of .
Twilight Prophet 
Creature — Vampire Cleric · 2/4 · Mythic · Rivals of Ixalan Promos · #88s
Flying
Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
At the beginning of your upkeep, if you have the city's blessing, reveal the top card of your library and put it into your hand. Each opponent loses X life and you gain X life, where X is that card's mana value.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
9 printings · $3.49 to $13.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander Masters | 193 | Mythic | $3.99 | $7.99 |
| Commander Masters | 524 | Mythic | — | — |
| The Lost Caverns of Ixalan Commander | 211 | Mythic | $3.49 | — |
| Murders at Karlov Manor Commander | 143 | Mythic | $3.99 | — |
| The List | RIX-88 | Mythic | $3.49 | — |
| Rivals of Ixalan Promos | 88p | Mythic | $13.99 | $7.99 |
| Rivals of Ixalan Promos | 88s | Mythic | — | $13.99 |
| Rivals of Ixalan | 88 | Mythic | $3.99 | $13.99 |
| Secret Lair Drop | 1304 | Mythic | $7.49 | $8.49 |
11 rulings from Wizards of the Coast
- 19 January 2018If you cast a spell with ascend, you don't get the city's blessing until it resolves. Players may respond to that spell by trying to change whether you get the city's blessing.
- 19 January 2018If the mana cost of the revealed card includes {X}, X is considered to be 0.
- 19 January 2018Once you have the city's blessing, you have it for the rest of the game, even if you lose control of some or all of your permanents. The city's blessing isn't a permanent itself and can't be removed by any effect.
- 19 January 2018In a Two-Headed Giant game, Twilight Prophet's last ability causes the opposing team to lose twice X life and you gain X life.
- 19 January 2018If your tenth permanent enters the battlefield and then a permanent leaves the battlefield immediately afterwards (most likely due to the "Legend Rule" or due to being a creature with 0 toughness), you get the city's blessing before it leaves the battlefield.
- 19 January 2018The mana value of a split card, such as cards with aftermath from the Amonkhet block, is based on the combined mana cost of its two halves.
- 19 January 2018Ascend on a permanent isn't a triggered ability and doesn't use the stack. Players can respond to a spell that will give you your tenth permanent, but they can't respond to getting the city's blessing once you control that tenth permanent. This means that if your tenth permanent is a land you play, players can't respond before you get the city's blessing.
- 19 January 2018If the revealed card doesn't have a mana cost (because it's a land card, for example), its mana value is 0.
- 19 January 2018A permanent is any object on the battlefield, including tokens and lands. Spells and emblems aren't permanents.
- 19 January 2018Some cards have triggered abilities with an intervening "if" clause that checks whether you have the city's blessing. These are worded "[Trigger condition], if you have the city's blessing, [effect]." You must already have the city's blessing in order for these abilities to trigger; otherwise they do nothing. In other words, there's no way to have the ability trigger if you don't have the city's blessing, even if you intend to get it in response to the triggered ability.
- 19 January 2018If you control ten permanents but don't control a permanent or resolving spell with ascend, you don't get the city's blessing. For example, if you control ten permanents, lose control of one, then cast Golden Demise, you won't have the city's blessing and the spell will affect creatures you control.