Cheapest priced copy (The List): $1.79 at Card Kingdom, near mint, their price list as of .
Cavalier of Flame 
Creature — Elemental Knight · 6/5 · Mythic · Core Set 2020 · #125
{1}{R}: Creatures you control get +1/+0 and gain haste until end of turn.
When this creature enters, discard any number of cards, then draw that many cards.
When this creature dies, it deals X damage to each opponent and each planeswalker they control, where X is the number of land cards in your graveyard.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $1.79 to $16.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Core Set 2020 | 125 | Mythic | $1.99 | $16.99 |
| The List | M20-125 | Mythic | $1.79 | — |
| Core Set 2020 Promos | 125p | Mythic | $6.49 | $15.99 |
| Core Set 2020 Promos | 125s | Mythic | — | $13.99 |
2 rulings from Wizards of the Coast
- 12 July 2019As Cavalier of Flame’s enters-the-battlefield ability resolves, you may choose to discard zero cards. You just won’t draw any cards.
- 12 July 2019In a Two-Headed Giant game, Cavalier of Flame’s last ability causes the opposing team to be dealt X damage twice.