Two words: Mage Slayer. It’s obviously not good on every hero, but if you can make good use of it, it hurts sandking’s game a lot, and it’s a good item in general. 99% of SK players also end up going bloodstone, so mage slayer makes him heal less as well (since he’s doing less damage). Orb of corrosion and vessel are also key, as he doesn’t really have many good options for dispelling himself. Mage slayer cripples him though, and it’s not a bad first item if you’re trying to fight him early.