Cheapest priced copy (Doctor Who): $0.49 at Card Kingdom, near mint, their price list as of .
Idris, Soul of the TARDIS 
Legendary Creature — Human Incarnation · 3/3 · Rare · Doctor Who · #419
Vanishing 3
Imprint — When Idris enters, exile another artifact you control until Idris leaves the battlefield.
Idris has all activated and triggered abilities of the exiled card and gets +X/+X, where X is the exiled card's mana value.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
4 printings · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Doctor Who | 135 | Rare | $0.49 | $0.49 |
| Doctor Who | 419 | Rare | $0.49 | $0.49 |
| Doctor Who | 740 | Rare | — | $0.49 |
| Doctor Who | 1010 | Rare | — | $0.49 |
3 rulings from Wizards of the Coast
- 13 October 2023Triggered abilities use the word "when," "whenever," or "at." They're often written as "[Trigger condition], [effect]." Some keyword abilities, such as prowess, are triggered abilities and will have "when," "whenever," or "at" in their reminder text.
- 13 October 2023If the exiled card has an {X} in its mana cost, the value of X is 0 when determining that card's mana value.
- 13 October 2023Activated abilities contain a colon. They're generally written "[Cost]: [Effect]." Some keyword abilities, like equip, are activated abilities and they have colons in their reminder text.