Inferior Demonbane is a spell within the Arceuus spellbook that requires level 44 Magic to be cast. This spell has a base max hit of 16, but can only be cast on demonic creatures.
By default, demonbane spells have an accuracy bonus of 20%, but can be doubled to 40% when the Mark of Darkness spell is active, which additionally gives a 25% damage bonus. If attacking with a purging staff, this is further doubled to an 80% accuracy and 50% damage bonus when under the effects of the Mark of Darkness. All of these bonuses are calculated after the player's own magic damage bonuses from their equipment.
Damage
Calculator
module = Magic damage calculator
form=MagicDamageCalc
result=MagicDamageResults
name =
param = spell|Spell|Inferior Demonbane|hidden|Inferior Demonbane
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),Purging staff
param = castMarkOfDarkness|Mark of Darkness|false|check
autosubmit = disabled
44 
1
Prayer used
Alt
Alt
