Predecessor Builds > Sparrow > brawler sparrow
for brawl mode, build is mostly focused on attack speed and physical power, can take most hero's from full health to 0 pretty quick with the right push, extremely viable with a good support behind you.
upgrade her charge shot and hail of arrows at the start then her focus(attack speed) ability when you level up about a minute in. maxing out her charge shot first will be important for the enemies that are faster and can get/stay out of your range. hail of arrows close behind for slowing enemies to get out if their range or to keep enemies in yours. focus ability is less important as your items will be where most your attack speed comes from
quiver and sky spliter can swap what's bought first depending if you prioritize lifesteal or attack speed, vanquisher can be bought third if you have a lot of kills just barely escaping. demolisher can be traded for whatever you feel like if there's not many tanks characters but the game will usually be close to over by the time your ready to buy it
THIS BUILD HAS NO ESCAPE. if you aren't confident knowing when to push or pull back. or have problems with CC. then go with the Pacificier to give yourself some leg room on escaping. sparrow is squishy so you will die quickly if you let yourself get CC'd at a bad time. I would recommend a different character if you aren't comfortable being aggressive, sparrow dies quick if you aren't prepared to fight back hard.