Cheapest priced copy (Kamigawa: Neon Dynasty): $3.99 at Card Kingdom, near mint, their price list as of .
Isshin, Two Heavens as One 
Legendary Creature — Human Samurai · 3/4 · Rare · Kamigawa: Neon Dynasty · #328
If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
8 printings · $3.99 to $74.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Final Fantasy: Through the Ages (Lightning, Lone Commando) | 54 | Rare | $9.49 | $74.99 |
| Kamigawa: Neon Dynasty | 224 | Rare | $3.99 | $3.99 |
| Kamigawa: Neon Dynasty | 328 | Rare | $6.49 | $16.99 |
| Kamigawa: Neon Dynasty | 488 | Rare | $4.49 | $8.99 |
| Kamigawa: Neon Dynasty Promos | 224p | Rare | $4.99 | $7.99 |
| Kamigawa: Neon Dynasty Promos | 224s | Rare | — | $6.49 |
| Stardates (Janeway, Cracked Mirror) | 19 | Mythic | — | — |
| Secret Lair Drop (Joshua Graham, Burned Man) | 2459 | Rare | $7.49 | $8.99 |
2 rulings from Wizards of the Coast
- 18 February 2022Isshin, Two Heavens as One's ability affects only triggered abilities with conditions that are directly related to attacking, such as “whenever [this creature] attacks” or “whenever you attack with one or more creatures.” It does not affect triggered abilities with other trigger conditions, such as “whenever [this creature] becomes tapped.”
- 18 February 2022Isshin's effect doesn't copy the triggered ability; it just causes the ability to trigger twice. Any choices made as you put the ability onto the stack, such as modes and targets, are made separately for each instance of the ability. Any choices made on resolution are also made individually.