Cheapest priced copy (Khans of Tarkir): $4.49 at Card Kingdom, near mint, their price list as of .
Temur Ascendancy 
Enchantment · Rare · Khans of Tarkir · #207
Creatures you control have haste.
Whenever a creature you control with power 4 or greater enters, you may draw a card.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
5 printings · $4.49 to $37.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Khans of Tarkir | 207 | Rare | $4.49 | $13.99 |
| Khans of Tarkir Promos | 207p | Rare | $7.49 | $14.99 |
| Khans of Tarkir Promos | 207s | Rare | — | $18.99 |
| Tarkir: Dragonstorm Commander | 305 | Rare | $4.49 | — |
| Time Spiral Remastered | 387 | Special | $4.99 | $37.99 |
3 rulings from Wizards of the Coast
- 19 March 2021Once the last ability of Temur Ascendancy has triggered, lowering the power of the creature won't stop you from drawing a card.
- 19 March 2021If Temur Ascendancy leaves the battlefield, creatures you control lose haste. If they haven't been under your control since the turn began and don't otherwise have haste, they can't attack this turn. If they've already attacked, they remain attacking creatures.
- 19 March 2021If a creature is entering the battlefield under your control, consider static abilities to determine whether its power is 4 or greater. Spells, activated abilities, and triggered abilities can't be used to raise the creature's power in time to have Temur Ascendancy's last ability trigger or to lower it in time to stop it from triggering.