17 cards where (the lore includes “rem” and the lore includes “karolus”)

Cathar's Companion (Jumpstart #94)
Celestial Judgment (Midnight Hunt Commander #5)
Clear Shot (Double Masters #159)
Demolish (Avacyn Restored #132)
Dismantling Blow (Modern Horizons #5)
Frenzied Devils (Innistrad: Crimson Vow #159)
Gloomwidow (Shadows over Innistrad #206)
Guise of Fire (Avacyn Restored #137)
Hellrider (Jumpstart #334)
Howling Banshee (Foundations Jumpstart #119)
Lambholt Elder // Silverpelt Werewolf (Dark Ascension #122)
Lambholt Elder // Silverpelt Werewolf (Dark Ascension #122)
Rem Karolus, Stalwart Slayer (Innistrad: Midnight Hunt #235)
Rem Karolus, Stalwart Slayer // Rem Karolus, Stalwart Slayer (Midnight Hunt Art Series #67)
Rem Karolus, Stalwart Slayer // Rem Karolus, Stalwart Slayer (Midnight Hunt Art Series #67)
Saint Traft and Rem Karolus (March of the Machine Commander #9)
Shattered Perception (Dark Ascension #104)
Slayer's Cleaver (Eldritch Moon #198)
Tribute to Hunger (Foundations #614)

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