FOILCheapest priced copy (Final Fantasy: Through the Ages): $5.49 at Card Kingdom, near mint, their price list as of .
Varragoth, Bloodsky Sire 
Legendary Creature — Demon Rogue · 2/3 · Rare · Kaldheim Promos · #115s
Deathtouch
Boast — {1}{B}: Target player searches their library for a card, then shuffles and puts that card on top. (Activate only if this creature attacked this turn and only once each turn.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
6 printings · $4.99 to $15.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Final Fantasy: Through the Ages (Ardyn Izunia) | 37 | Rare | $5.49 | $12.99 |
| Kaldheim | 115 | Rare | $5.99 | $4.99Out of stock |
| Kaldheim | 309 | Rare | $5.99 | $7.99Out of stock |
| Kaldheim Promos | 115p | Rare | $5.99 | $15.99 |
| Kaldheim Promos | 115s | Rare | — | $6.99Out of stock |
| Secret Lair Drop (Tiffany, Bride of Chucky) | 1809 | Rare | $6.49 | $8.99 |
4 rulings from Wizards of the Coast
- 5 February 2021If it's not your turn and you gain control of a creature with a boast ability after that creature attacked, you can activate that creature's boast ability if it hasn't been activated yet that turn.
- 5 February 2021If an effect adds additional combat phases to a turn and a creature with a boast ability attacks more than once during that turn, its boast ability can still be activated only once.
- 5 February 2021A boast ability can be activated at any point after the creature with that ability has been declared as an attacker. This can be before blockers are declared, after blockers are declared but before combat damage is dealt, during combat after combat damage is dealt, during the postcombat main phase, during the end step, or, in some unusual cases, during the cleanup step.
- 5 February 2021If a creature with a boast ability is put onto the battlefield attacking, it was never declared as an attacker. Its boast ability can't be activated that turn.