Given that Shadow Barrage is the most expensive spell on the spellbook, it is rarely used, as Smoke Barrage offers significantly better cost efficiency and both Blood Barrage and Ice Barrage offer both more damage per and less cost per cast.
Damage
Calculator
module = Magic damage calculator
form=MagicDamageCalc
result=MagicDamageResults
name =
param = spell|Spell|Shadow Barrage|hidden|Shadow Barrage
param = magicStrength|Visible % Magic strength|0|number|-80-100
param = specialModifier|Special modifiers|None|select|None,Slayer helmet (i),Salve amulet (i),Salve amulet (ei),Amulet of avarice (Revenants)|Amulet of avarice (Revenants)=haveForinthrySurge
param = haveForinthrySurge|Have Forinthry Surge|false|check|||Forinthry Surge is a buff acquired by defeating the Revenant maledictus while wearing an Amulet of avarice
param = weapon|Weapon effect|None|select|None,Thammaron's sceptre (Wilderness),Accursed sceptre (Wilderness),Dragon hunter wand
autosubmit = disabled
In addition to dealing damage, Shadow Barrage reduces the target's Attack level by 15% if it has not already been drained. This effect does not stack to lower the target's Attack level to zero, and will not apply if the target's stats have already been drained from another source.
When used against the Abyssal Sire, Shadow Barrage has a 100% chance of disorienting it for the first phase of the fight. Contrary to popular belief, the spell does not offer this effect against standard abyssal demons, and will simply reduce their Attack by 15% like normal.
Players can also cast Shadow Barrage to stun the Leviathan, resulting in a guaranteed hit that will cause it to stay still for 15 ticks (9 seconds), allowing players to safely deal damage. This will reset the Leviathan's attack speed to the beginning of the 2-tick attacks.