FOILCheapest priced copy (Khans of Tarkir): $0.49 at Card Kingdom, near mint, their price list as of .
Dragon-Style Twins 
Creature — Human Monk · 3/3 · Rare · Khans of Tarkir Promos · #108s
Double strike
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.49 to $0.69 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Khans of Tarkir | 108 | Rare | $0.49 | $0.49 |
| Khans of Tarkir Promos | 108s | Rare | — | $0.69 |
3 rulings from Wizards of the Coast
- 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.
- 20 September 2014Prowess goes on the stack on top of the spell that caused it to trigger. It will resolve before that spell.