mtg protection cards Teferi's (foil etched) Strixhaven Mystical Archives (011/063) They phase in before you untap during your untap step.) Exile Teferis Protection. Protection in MTG - Rules,

As a 5-color deck, cards like Birds of Paradise, Ignoble Hierarch, and Rivaz of the Claw are good to use

Thirst (Mirage/Visions/Weatherlight) Blue doesn't get removal spells often, and they usually aren't in the common slot

So, first things first about the Sliver deck

It runs a few board wipes including Nevinyrral's Disk, but it doesnt seem to have an endgame besides to tick up Teferi and cast a big creature like Deep-Sea Kraken, Sphinx of Magosi, or the previously mentioned Lorthos, the Tidemaker

As of right now, Golgari is underdrafted, and I'm still seeing Cloud of Darkness deep into pack one, which is no longer the case for cards like Shantotto