The Wind Striker Aspect is perhaps the most useful one among all general (non-class specific) legendary aspects in Diablo 4.
It is a mobility aspect that grants you a massive burst of speed to quickly reposition yourself or chase down enemies.
The speed-burst lasts for only a second but since you trigger the Wind Striker Aspect by landing critical strikes, you can technically get multiple bursts of speed during the same encounter.
Wind Striker Aspect location in Diablo 4
The Wind Striker Aspect can be found in the western part of Sanctuary and in the Amber Sands Sub-region. This Sub-region is located in Kehjistan. The Wind Striker is found as a reward when you complete the Shivta Ruins.
From the Shivta Ruins, the closest waypoint you can use is in the Altar of Ruin Stronghold. From the stronghold take the southern exit and then move northeast towards the shrine and the Dungeon.
If you have not completed the Stronghold, you can approach the Shivta Ruins from the Iron Wolves Encampment waypoint. From there you will have to first move north and then move north-east until you reach the dungeon.
Near the Dungeon, you will find many dungeons such as Inferno, Collapsed Vault, Tomb of the Saints, and Sunken Library.
When you enter the dungeon, you will have a few objectives you need to complete in order to confront the final boss and get the Wind striker aspect.
The first objective is to return 2 Bloodstones to the pedestals. This will open up the path to the Shambles of Vermin. Here you will need to defeat the Seething Hivemaster.
Wind Striker Aspect builds in Diablo 4
There are several builds that prioritize critical strike stats, all of which can make use of the Wind Striker Aspect for a massive but short-lived burst of speed in Diablo 4.
Take for example the Bone Spear build and Bone Spirit build for Necromancer, as well as the Whirlwind Barbarian build.
Both mentioned Necromancer builds make use of Bone skills to do a ton of damage thanks to critical strike multipliers. The Barbarian build, on the other hand, can me good use of the Wind Striker Aspect to catch fleeting enemies or cover more ground while your Fury lasts.