Cheapest priced copy (Modern Horizons 3): $7.99 at Card Kingdom, near mint, their price list as of .
Ashling, Flame Dancer 
Legendary Creature — Elemental Shaman · 4/4 · Mythic · Modern Horizons 3 · #115
You don't lose unspent red mana as steps and phases end.
Magecraft — Whenever you cast or copy an instant or sorcery spell, discard a card, then draw a card. If this is the second time this ability has resolved this turn, Ashling deals 2 damage to each opponent and each creature they control. If it's the third time, add {R}{R}{R}{R}.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
6 printings · $7.99 to $32.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Modern Horizons 3 | 115 | Mythic | $7.99 | $8.99 |
| Modern Horizons 3 | 367 | Mythic | $15.99 | $32.99 |
| Modern Horizons 3 | 415 | Mythic | $8.49 | $16.99 |
| Modern Horizons 3 | 481 | Mythic | — | — |
| The List | MH3-115 | Mythic | — | — |
| Modern Horizons 3 Promos | 115s | Mythic | — | $15.99 |
5 rulings from Wizards of the Coast
- 7 June 2024Once Ashling leaves the battlefield, you have until the end of the current step or phase to spend whatever red mana you have before you lose that mana as normal. There is no penalty associated with this other than the loss of the mana.
- 7 June 2024If an effect creates multiple copies of an instant or sorcery spell, Ashling's last ability triggers once for each copy created by the effect.
- 7 June 2024If a red mana you add has certain restrictions or riders associated with it (for example, if it was produced by the last ability of Arena of Glory), they'll apply to that mana no matter when you spend it.
- 7 June 2024You can keep unspent red mana indefinitely while Ashling is on the battlefield. That means if you add a red mana during one step or phase, you can spend it during a later step or phase, or even a later turn. You will still lose other types of unspent mana as each step and phase ends.
- 7 June 2024Some effects instruct you to copy an instant or sorcery card in a zone other than the stack. These copies will not cause Ashling's last ability to trigger. However, most effects that do this also allow you to cast the copy, and casting the copy will cause Ashling's last ability to trigger.