Cheapest priced copy (Double Masters 2022): $0.35 at Card Kingdom, near mint, their price list as of .
Monastery Swiftspear 
Creature — Human Monk · 1/2 · Uncommon · Khans of Tarkir · #118
Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Legal inCommanderPioneerModernLegacyVintage
Banned inPauper
Not legal inBrawlStandard
11 printings · $0.35 to $74.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters 2022 | 119 | Common | $0.39 | $0.49 |
| Double Masters 2022 | 362 | Common | $0.35 | $0.79 |
| The Brothers' War | 144 | Uncommon | $0.39 | $0.49 |
| Iconic Masters | 140 | Uncommon | $0.49 | $1.99 |
| Khans of Tarkir | 118 | Uncommon | $0.49 | $5.99 |
| The List | IMA-140 | Uncommon | $0.49 | — |
| Store Championships | 27 | Rare | $1.49 | — |
| Secret Lair Drop | 216 | Rare | $10.99 | $8.99 |
| Secret Lair Drop | 2038 | Rare | $6.99 | $6.49 |
| Secret Lair Drop | 2043 | Rare | — | $9.99 |
| Time Spiral Remastered | 349 | Special | $3.99 | $74.99 |
4 rulings from Wizards of the Coast
- 20 September 2014Prowess goes on the stack on top of the spell that caused it to trigger. It will resolve before that spell.
- 20 September 2014Once it triggers, prowess isn't connected to the spell that caused it to trigger. If that spell is countered, prowess will still resolve.
- 20 September 2014Any spell you cast that doesn't have the type creature will cause prowess to trigger. If a spell has multiple types, and one of those types is creature (such as an artifact creature), casting it won't cause prowess to trigger. Playing a land also won't cause prowess to trigger.
- 19 March 2021An ability that triggers when a player casts a spell resolves before the spell that caused it to trigger. It resolves even if that spell is countered.