Stealth is my favorite way to play the game, so this build came pretty naturally. I'll try and not make it as winded as my first build lol.
Widowmaker is an assassin and a sniper- the best there is. Brainwashed into becoming evil, she's now a walking weapon.
Stones: Thief, Shadow, and Serpent. Take Thief early on, change for one of the other two later if you so desire.
Race: Dark Elf or Wood Elf. I'd go Dark Elf for aesthetic reasons, though.
Shouts: Aura Whisper. This is your main way of finding enemies and setting up a shot. Become Ethereal and Whirlwind Sprint for quick escapes (we don't have a grappling hook so we have to make due).
You are, for the most part, a long range sniper. BUT if you're feeling brave, you can stick poisons into your enemies' pockets (in place of venom mine).
I didn't fill out the entire Archery tree to make it feel as close to OG Widowmaker as possible (slow moving while scoped/bow drawn, no paralyzing shots, etc). But you can do you once you get past the level needed to complete this build. One handed is backup only, as we don't have an SMG to shoot if someone gets too close. Although, if you want to trade out one handed completely for rapid fire shots, go for it. If you do that, I recommend getting Zephyr AND the Quick Draw perk. If they stack. I don't remember if they do.
If you're going for a roleplay build- simply put, you're evil. You're manipulated into being evil. Join the Dark Brotherhood, but NOT the Thieves' Guild.
You'll become a Vampire, as Widowmaker's heart was slowed and she's cold to the touch. Obviously you can get more perks as you level, but the 5 Vampire perks I picked are essential for a Widow-based build.
Hope you enjoy