So instead of using your burn to directly attack their opponent, remove their lifelink creatures with it instead
Altanak, the Thrice-Called Anara, Wolvid Familiar Brokkos, Apex of Forever Brokkos, Apex of Forever Fortune, Loyal Steed Gahiji, Honored One Galian Beast Illuna, Apex of Wishes Illuna, Apex of Wishes Kaheera, the Orphanguard Kethek, Crucible Goliath Kona, Rescue Beastie Lagorin, Soul of Alacria Loot, Exuberant Explorer Loot, the Key to Everything Loot, the Pathfinder Marath, Will of the Wild Migloz, Maze Crusher Nethroi, Apex of Death Nethroi, Apex of Death Nyla, Shirshu Sleuth Otrimi, the Ever-Playful Questing Beast Ragnarok, Divine Deliverance Red XIII, Proud Warrior Slinza, the Spiked Stampede Tayam, Luminous Enigma Uril, the Miststalker Uurg, Spawn of Turg Yannik, Scavenging Sentinel
Like most Magic: The Gathering cards, the value of Grim Initiate depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (War of the Spark)
Video Overview So without wasting any more time, lets get into it
Other cards have done poorly, even when protected by the Reserved list, loosing value over the years