Cheapest priced copy (Oath of the Gatewatch): $0.35 at Card Kingdom, near mint, their price list as of .
Kozilek's Pathfinder 
Creature — Eldrazi · 5/5 · Common · Oath of the Gatewatch · #5
{C}: Target creature can't block this creature this turn. ({C} represents colorless mana.)
Legal inCommanderPioneerModernLegacyVintagePauper
Not legal inBrawlStandard
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Oath of the Gatewatch | 5 | Common | $0.35 | $0.49 |
One ruling from Wizards of the Coast
- 22 January 2016Activating the ability once Kozilek’s Pathfinder has been legally blocked won’t change or undo that block.