Open a pack and you get some cards
If you revealed "Gunkan Suship Shari" in your hand at activation, you can choose the card to add to your hand, instead of your opponent choosing
It's around #14 or 15 on my list and not in the Top 10 proper, but the ability to force someone to discard, and destroy artifacts and critters with one number is a very precise scalpel that destroys what you need, but tends to leave your own stuff alone
There are a handful of effects that directly benefit you for playing Spirits, such as Battleground Geist, which gives all of your spirits +1/+0 , or Spectral Shepherd, which allows you to bounce a Spirit back to your hand to avoid death or get a second use out of its enter effect

Table of Contents show The Deck Rat Colony | Illustration by Suzanne Helmigh Commander (1) Creature (46) Accursed Marauder Ayara, First of Locthwain Blood Artist Boggart Trawler God-Eternal Bontu Grim Haruspex Karumonix, the Rat King Lord Skitter, Sewer King Marrow-Gnawer Midnight Reaper Ogre Slumlord Plaguecrafter Rat Colony x32 Vengeful Bloodwitch Zulaport Cutthroat Instant (3) Fell the Profane Hagra Mauling Plumb the Forbidden Sorcery (2) Agadeem's Awakening Bloodline Bidding Enchantment (1) Artifact (14) Altar of Dementia Arcane Signet Charcoal Diamond Fellwar Stone Gathering Stone Jet Medallion Magewright's Stone Mind Stone Phyrexian Altar Sceptre of Eternal Glory Skullclamp Sting, the Glinting Dagger Thought Vessel Throne of Eldraine Land (33) Cabal Coffers Castle Locthwain Cavern of Souls Crypt of Agadeem Phyrexian Tower Secret Tunnel Spymaster's Vault Susur Secundi, Void Altar Swamp x22 Takenuma, Abandoned Mire Urborg, Tomb of Yawgmoth War Room Verminister leads a Rat Colony deck with an emphasis on sacrifice effects to maximize the potential of Rat King, Verminister

Like Szarekh, Anrakyr has an attack trigger, but does far more than draw you a card, instead cheating mana costs by letting the player use their life total for a single artifact spell