Memory Erosion [Mystery Booster] Living Card Game When the Brotherhood of Gix

When the Brotherhood of Gix dug out the cave of Koilos they found their master's severed hand

Set: Future Sight Type: Instant Rarity: Rare Cost: {0} Counter target spell

Set: Mirage Type: Enchantment Rarity: Rare Cost: {3}{B}{G} Exile a card from your hand: Add {B}{B} or {G}{G}

This explains why the goblins remain unaffected

When Saproling Burst leaves the battlefield

Memory Erosion [Mystery Booster] Living Card Game When the Brotherhood of GixSet: Mystery Booster Type: Enchantment Rarity: Rare Cost: {1}{U}{U} Whenever an opponent casts a spell, that player mills two cards. "The Filigree Texts do not compel you to act in accordance with their precepts. They only specify the consequences should you fail." Lodus of the Ethersworn