18 cards where the set is “akh” and the cards are exclusive Planeswalker Deck cards

Gideon, Martial Paragon (Amonkhet #270)
Companion of the Trials (Amonkhet #271)
Gideon's Resolve (Amonkhet #272)
Graceful Cat (Amonkhet #273)
Stone Quarry (Amonkhet #274)
Liliana, Death Wielder (Amonkhet #275)
Desiccated Naga (Amonkhet #276)
Liliana's Influence (Amonkhet #277)
Tattered Mummy (Amonkhet #278)
Foul Orchard (Amonkhet #279)
Cinder Barrens (Amonkhet #280)
Forsaken Sanctuary (Amonkhet #281)
Highland Lake (Amonkhet #282)
Meandering River (Amonkhet #283)
Submerged Boneyard (Amonkhet #284)
Timber Gorge (Amonkhet #285)
Tranquil Expanse (Amonkhet #286)
Woodland Stream (Amonkhet #287)

The message was clear to Sorin—time to search for something else.