Cheapest priced copy (Double Masters 2022): $5.99 at Card Kingdom, near mint, their price list as of .
Master of Cruelties 
Creature — Demon · 1/4 · Mythic · Dragon's Maze · #82
First strike, deathtouch
This creature can only attack alone.
Whenever this creature attacks a player and isn't blocked, that player's life total becomes 1. This creature assigns no combat damage this combat.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
9 printings · $5.99 to $17.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters 2022 | 251 | Mythic | $5.99 | $6.99 |
| Double Masters 2022 | 522 | Mythic | — | — |
| Dragon's Maze | 82 | Mythic | $7.49 | $11.99 |
| RNA Guild Kit | 66 | Mythic | $6.49 | — |
| The List | DGM-82 | Mythic | $6.99 | — |
| Ravnica Remastered | 198 | Mythic | $6.49 | $5.99 |
| Ravnica Remastered | 373 | Mythic | $6.49 | $7.99 |
| Ravnica Remastered | 373z | Mythic | — | — |
| Secret Lair Drop | 1565 | Mythic | $17.99 | $11.99 |
6 rulings from Wizards of the Coast
- 15 April 2013If Master of Cruelties attacks alone, another creature entering the battlefield attacking will have no effect on it. Master of Cruelties continues to be an attacking creature. The other attacking creature will assign combat damage normally, regardless of whether Master of Cruelties's last ability triggers.
- 15 April 2013For a player's life total to become 1, what actually happens is that the player loses (or in some rare cases, gains) the appropriate amount of life. For example, if the player's life total is 4 when the last ability resolves, it will cause that player to lose 3 life. Other effects that interact with life loss (or gain) will interact with this effect accordingly.
- 15 April 2013Assigning no combat damage isn't the same as preventing that damage. Effects that make damage unpreventable will have no effect if no combat damage can be assigned.
- 15 April 2013Master of Cruelties isn't forced to attack, but if it does, it must do so alone. If you control another creature with an ability that says it must attack if able, that creature must attack and Master of Cruelties won't be able to.
- 15 April 2013An ability that triggers when something "attacks and isn't blocked" triggers in the declare blockers step after blockers are declared if (1) that creature is attacking and (2) no creatures are declared to block it. It will trigger even if that creature was put onto the battlefield attacking rather than having been declared as an attacker in the declare attackers step.
- 12 January 2024Master of Cruelties's last ability won't trigger if it attacks a planeswalker or a battle.