Cheapest priced copy (Ravnica Remastered): $1.79 at Card Kingdom, near mint, their price list as of .
Gideon Blackblade 
Legendary Planeswalker — Gideon · Mythic · War of the Spark · #13★
During your turn, Gideon Blackblade is a 4/4 Human Soldier creature with indestructible that's still a planeswalker.
Prevent all damage that would be dealt to Gideon Blackblade during your turn.
+1: Up to one other target creature you control gains your choice of vigilance, lifelink, or indestructible until end of turn.
−6: Exile target nonland permanent.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
8 printings · $1.49 to $74.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mythic Edition | WS2 | Mythic | — | $10.99 |
| War of the Spark Promos | 13p | Mythic | $4.49 | $8.99 |
| War of the Spark Promos | 13s | Mythic | — | $4.99 |
| War of the Spark Promos | 13s★ | Mythic | — | $74.99 |
| Ravnica Remastered | 20 | Mythic | $1.79 | $1.49 |
| Secret Lair Drop | 503 | Mythic | — | $2.79 |
| War of the Spark | 13 | Mythic | $1.99 | $1.99 |
| War of the Spark | 13★ | Mythic | $1.79 | $24.99 |
5 rulings from Wizards of the Coast
- 3 May 2019If an Equipment becomes attached to Gideon while he's a creature, it'll become unattached during the next upkeep that isn't yours. The same is true of any Auras that become attached to Gideon that can't enchant a noncreature planeswalker.
- 3 May 2019Any counters that are put on Gideon remain on him while he's not a creature, even if they have no effect on a noncreature planeswalker.
- 3 May 2019If damage that can't be prevented is dealt to Gideon during your turn, that damage will have all applicable results: specifically, the damage is marked on Gideon (since he's a creature) and that damage causes that many loyalty counters to be removed from him (since he's a planeswalker). Even though he has indestructible, if Gideon has no loyalty counters on him, he's put into his owner's graveyard.
- 3 May 2019If an effect causes Gideon to lose all abilities during your turn, he's still a Human Soldier creature and a Gideon planeswalker. This is because his first ability applies before that ability is lost.
- 3 May 2019You choose which ability the target creature gains as Gideon's first loyalty ability resolves, not as you activate it.