Rain of Arrows functions by resetting its cooldown constantly through Preparation. We use Heartseeker with Shard of Verathiel and Lucion Crown for that purpose. Later on, when we have access to Chaotic Uniques, we will use Puncture to bypass Ophan Maker's Reload.
Season 10 brings powerful buffs in the form of Chaotic Uniques and new Uniques.
Being able to slot Word of Hakan somewhere that isn't our Amulet is hugely beneficial for the build, as Amulets are the highest damage item.
Orphan Maker is also a huge endgame buff to the build, as its stats are fantastic for the build.
Leveling
You can't level with this build as it requires Uniques to function.
Consider leveling with Dance of Knives, as it is by far the strongest leveling build.
Mercenaries
We will use Subo with Wire Tap for more Movement Speed and Cover Fire for more Critical Strike Damage.
Raheir is also an option if we lack tankiness, as he can provide Armor and Fortify.
For our reinforcement Mercenary, we will use Raheir with Crater to pull in. If we are already using Raheir as our main Mercenary, we will use Aldkin with Field of Langush for more Damage Reduction.
Chaos Perks
We will use A Beast Cornered, in combination with Marred Guard, to do a lot more damage and become incredibly tanky.
Crazy Brew will help us by giving more Attack Speed.
Lastly, Unpredictable Alchemy will increase our damage.
Runes
Initially, we will use Zan + Zec to help lower the Cooldown of Rain of Arrows.
We will also use Poc + Thul for more damage.
Later on, we will use Zan + Jah for Mobility and Poc + Xan for even more damage.
When Pit Pushing, we will replace Jah with Ohm.
Elixirs and Incenses
It's important to run Elixirs and Incenses at all times. Not only because they increase our Experience gain but also because they provide very strong combat boosts.
For Elixirs, we will use Elixir of Advantage for Attack Speed.
For Incenses, we will use Queen's Supreme for Dexterity, Song of the Mountain for Armor and Soothing Spices for All Resistances and more Armor.
Cooldown Reduction
You can use THIS Sheet to calculate your Rain of Arrows Cooldown by making a Copy. We need the cooldown to be 10 seconds.
Attack Speed Breakpoints
Because the game's server operates in frames (images), Skills can only be cast in a whole number of frames. This means, for example, that you can't cast a Skill in 10.2 frames. To extend this example further, that means that all Attack Speed values that lead to a cast time of 10.01 to 10.99 frames would mean you end up casting at 11 frames, effectively wasting all Attack Speed gains from 11 frames to 10.01.
In order to avoid wasting Attack Speed, you can calculate the Attack Speed Breakpoints for your skills using THIS SHEET.
You might be wondering how frames translate into actual Cast Speed. Because the server runs at 60 frames per second the way we translate frames into Cast Speed is with the formula: 60 / Frames = Casts per Second.
Masterworking and Greater Affixes Explained
Both Masterworking and Tempering have been completely reworked in Season 11, which are set to give players more control over their gearing progression.
If you want to learn more about Masterworking and Tempering, check out our Masterworking and Tempering Guide.