Merfolk decks with Kopala, Warden of the Waves or Svyelun of Sea and Sky already make their board difficult to interact with by taxing their opponents - adding in another low mana value counterspell further improves the resilience of your already established board
Grabbing Pithing Needle can be essential in a variety of matchups, too, whether youre naming Goblin Bombardment out of Boros Energy or Goblin Charbelcher out of Belcher combo
Although Lifestream's Blessing's full potential only activates by paying its Foretell costs, keeping the card handy for the moment you set down a massive creature is a great way to avoid its cancellation while acting as an insurance policy for your life total
Does Sefris of the Hidden Ways use any infinite combos
The Mana Base (Ramp & Lands): The pre-con comes with many lands that enter the battlefield tapped, which can slow you down
Lots of Spellslinger decks add Red which gives you more ways to loot away flashback cards to cast from your graveyard later on, like Faithless Looting, but also powerhouse Spellslinger cards like Increasing Vengeance, Seize the Day, and best of all Past in Flames