Discarding even one before they get set up can hinder them severely
I see at least four, in fact: Let's Play a Game, Saw, The Lord of Pain, and Trial of Agony

MTG Assassin's Creed Starter Kit decklists ANCIENT ARSENAL (RED-WHITE) Eivor, Battle-Ready Escarpment Fortress Surtr, Fiery Jtun 3 Settlement Blacksmith 3 Keen-Eyed Raven 2 Spartan Veteran 3 Labyrinth Adversary 3 Bureau Headmaster Ezio, Brash Novice Arbaaz Mir Towering Viewpoint 2 Raven Clan War-Axe 2 Headsplitter 2 Hookblade 3 Detained by Legionnaires 2 Battlefield Improvisation 3 Stone Quarry 11 Plains 11 Mountain 3 Misthios's Fury BROTHERHOOD AGENTS (BLUE-BLACK) Achilles Davenport Ezio, Blade of Vengeance 2 Hookblade Veteran 3 Brotherhood Spy 2 Assassin Den 3 Merciless Harlequin 2 Brotherhood Patriarch 2 Poison-Blade Mentor 3 Brotherhood Ambushers 3 Hired Blade Assassin Initiate Towering Viewpoint 2 Auditore Ambush 3 Tranquilize Restart Sequence Eagle Vision Rooftop Bypass 3 Submerged Boneyard 11 Island 11 Swamp Chain Assassination Murder Collector Boosters Buying a Collector Booster for MTG Assassins Creed is the number one way to get your hands on Rare and Mythic Rare cards, extended arts, and both etched and textured foils

Its just a useful card to have available at all times during a game
We wanted to find out
At the moment, the card Great TUSK EX, Illustration rare is sold for around 25 euros