tempest, magmus, behemoth are all common picks and totally ruin your day, shroud or not. If your team has a stealth hero like scout or night hound, the other team is going to buy a lot of bound eyes and wards of revelation, so shroud is usually not a good idea then too.

Voodoo is usually a backliner, so many people don't actually get defensive items on him: his main purpose is to get off stun -> cursed ground and then sit there with scary totem gun. However, if your team is not reliable, torak is right that you'll need at least one defensive item (people usually opt for shrunken head or shroud). Codex, staff of master, or hellflower are oft-used picks with an offensive voodoo - they synergize well with cursed ground. I do not suggest upgrading your codex past level 1 until after you've built another item, though. At level 5, codex is the single most expensive item in the game, and quite frankly after the first 3k gold you don't need to put in another 5k for an extra 400 damage.

Another option for voodoo is the support build, which takes arcane ring and astrolabe and allows you to spam your healing spell over and over again, and keep your team at near full health the entire push - used primarily for fast games, where you have chars like hellbringer and ophelia letting your team push really hard really early with massive creep advantage.