13 cards where the name includes “relentless”

Eron the Relentless (Time Spiral Timeshifted #61)
Garruk Relentless // Garruk, the Veil-Cursed (Innistrad #181)
Garruk Relentless // Garruk, the Veil-Cursed (Innistrad #181)
Holga, Relentless Rager (Secret Lair Drop #1240)
Relentless Advance (War of the Spark #64)
Relentless Assault (Commander Legends #416)
Relentless Dead (Shadows over Innistrad #131)
Relentless Hunter (Battlebond #226)
Relentless Pursuit (Theros Beyond Death #195)
Relentless Raptor (Rivals of Ixalan #169)
Relentless Rats (Masters 25 #105)
Relentless Rohirrim (The Lord of the Rings: Tales of Middle-earth #144)
Relentless Skaabs (Duel Decks: Blessed vs. Cursed #46)
Vren, the Relentless (Bloomburrow #239)

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