Cheapest priced copy (Masters 25): $16.99 at Card Kingdom, near mint, their price list as of .
Luminarch Ascension 
Enchantment · Rare · Salvat 2011 · #13
At the beginning of each opponent's end step, if you didn't lose life this turn, you may put a quest counter on this enchantment. (Damage causes loss of life.)
{1}{W}: Create a 4/4 white Angel creature token with flying. Activate only if this enchantment has four or more quest counters on it.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
3 printings · $16.99 to $37.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Masters 25 | 23 | Rare | $16.99 | $37.99 |
| Salvat 2011 | 13 | Rare | — | — |
| Zendikar | 25 | Rare | $16.99 | $27.99 |
3 rulings from Wizards of the Coast
- 16 March 2018Luminarch Ascension's first ability doesn't trigger if you have lost life before an opponent's end step begins. If it does trigger but you lose life before it resolves, it does nothing and you won't put a quest counter on Luminarch Ascension.
- 16 March 2018Luminarch Ascension's first ability cares only whether you lost life this turn, even if Luminarch Ascension wasn't on the battlefield when that happened. It doesn't care how much you lost, whether you also gained life, or even whether you gained more life than you lost.
- 16 March 2018You can activate Luminarch Ascension's last ability during the end step in which it receives its fourth quest counter.