first edition mew pokemon card [1st Edition] #119 Prices | Japanese Expedition Expansion Pack A Near Mint card may have slight edge wear or a scratch or three Pokemon - Mew (8) -

Our best answer to it other than a Chalice of the Void for two is Mindbreak Trap

removing said named character to inhibit your combos

Once Brotherhood Spy's ability has resolved, removing the legendary Assassin (or Assassins) you control from the battlefield or causing them to lose the legendary supertype or Assassin subtype won't cause Brotherhood Spy's ability to stop applying for that turn

Since countering is all about controlling the stack, I figured it important to mention these spells that shield the stack from interaction

If you do, return this card from your graveyard to the battlefield with a finality counter on it