Cheapest priced copy (Throne of Eldraine): $0.35 at Card Kingdom, near mint, their price list as of .
Deathless Knight 
Creature — Skeleton Knight · 4/2 · Uncommon · Throne of Eldraine · #208
Haste
When you gain life for the first time each turn, return this card from your graveyard to your hand.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Throne of Eldraine | 208 | Uncommon | $0.35 | $0.49 |
| The List | ELD-208 | Uncommon | $0.35 | — |
2 rulings from Wizards of the Coast
- 4 October 2019If Deathless Knight enters your graveyard after you've gained life in a turn, its last ability can't trigger during that turn.
- 4 October 2019Deathless Knight must be in your graveyard immediately after you gain life for its last ability to trigger. If you gain life due to damage from a source with lifelink, and that damage is dealt at the same time that lethal damage is dealt to Deathless Knight, it won't be in your graveyard until state-based actions are performed a moment later, and so the ability can't trigger.