10 cards where the set is “thb” and the cards are exclusive to Theme Boosters

Grasping Giant (Theros Beyond Death #288)
Victory's Envoy (Theros Beyond Death #289)
Sphinx Mindbreaker (Theros Beyond Death #290)
Serpent of Yawning Depths (Theros Beyond Death #291)
Demon of Loathing (Theros Beyond Death #292)
Underworld Sentinel (Theros Beyond Death #293)
Deathbellow War Cry (Theros Beyond Death #294)
Terror of Mount Velus (Theros Beyond Death #295)
Ironscale Hydra (Theros Beyond Death #296)
Treeshaker Chimera (Theros Beyond Death #297)

Though this query has ended, its relics still slumber in New Argive.