Cheapest priced copy (Double Masters): $8.49 at Card Kingdom, near mint, their price list as of .
Sen Triplets 
Legendary Artifact Creature — Human Wizard · 3/3 · Mythic · Alara Reborn · #109
At the beginning of your upkeep, choose target opponent. This turn, that player can't cast spells or activate abilities and plays with their hand revealed. You may play lands and cast spells from that player's hand this turn.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
5 printings · $8.49 to $39.99 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Double Masters | 218 | Mythic | $8.49 | $11.99 |
| Alara Reborn | 109 | Mythic | $9.49 | $39.99 |
| The List | ARB-109 | Mythic | — | $8.49 |
| Stardates (Borg Queen, Hateful Legacy) | 16 | Mythic | — | — |
| Secret Lair Drop | 1198 | Mythic | — | $34.99Out of stock |
6 rulings from Wizards of the Coast
- 7 August 2020You can't activate abilities of cards in the target opponent's hand.
- 7 August 2020Abilities that create replacement effects, such as a permanent entering the battlefield tapped or with counters on it, are unaffected by Sen Triplets. Abilities that apply “as [this creature] enters the battlefield” are also replacement effects and are unaffected.
- 7 August 2020Activated abilities are written in the form “[Cost]: [Effect].” Some keyword abilities (such as cycling) are activated abilities and will have colons in their reminder texts.
- 7 August 2020Triggered abilities use the word “when,” “whenever,” or “at.” They're often written as “[Trigger condition], [effect].” Triggered abilities are unaffected by Sen Triplets.
- 7 August 2020Sen Triplets doesn't allow you to play more than one land during your turn or change when you may cast spells from the target opponent's hand.
- 7 August 2020The target opponent can't activate any abilities, including mana abilities.