Cheapest priced copy (Commander 2020): $0.49 at Card Kingdom, near mint, their price list as of .
Fireflux Squad 
Creature — Human Soldier · 4/3 · Rare · Commander 2020 · #51
Haste
Whenever this creature attacks, you may exile another target attacking creature you control. If you do, reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield tapped and attacking and the rest on the bottom of your library in a random order.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Commander 2020 | 51 | Rare | $0.49 | — |
4 rulings from Wizards of the Coast
- 17 April 2020If you exile your entire library without exiling a creature card, you put the library back in a random order and continue. You won’t return the exiled attacking creature. Oops.
- 17 April 2020You choose which player or planeswalker the new creature is attacking. It doesn’t have to be attacking the same player or planeswalker that Fireflux Squad or the exiled creature was attacking.
- 17 April 2020Although the new creature is an attacking creature, it was never declared as an attacking creature. This means that abilities that trigger whenever a creature attacks won’t trigger when it enters the battlefield attacking.
- 17 April 2020Any effects that say that the new creature can’t attack (such as that of Propaganda, or if you get a creature with defender) affect only the declaration of attackers. They won’t stop the creature you find from entering the battlefield attacking.