Arrow of Evil's Bane

The arrow is not notched and cannot be fired from a bow.  To be used the arrow must be dropped or thrown.  Once done the arrow will point to the strongest source of evil it senses within a one mile radius.  If the arrow has line of sight and can hit the source of evil it will target it and attack.  The arrow will hit the target unless dodged (20 dexterity save) and cannot be blocked with a shield or armor.  The arrow will do 5d10 radiant damage, doing an additional 2d10 damage to creatures with chaotic evil alignments.  The arrow will remain embedded in the creature and cannot be removed until the creature dies.  Once the creature is struck and has taken damage it will transform into it's purest evil form.  This can have random effects depending on the creature, its personality, deities it worships, etc.  If the creature is a fiend, dragon, or some other evil entity disguising itself with a spell the spell will be ended and the creature will revert to its true form.  If the arrow senses a strong enough presence of evil it can be used to track the presence over distances greater than a mile, for example a powerful demon or evil god that has entered the mortal plane.  While the arrow is hovering attempting to acquire a target it is vulnerable to anti magic fields and dispel magic, which will cause it to fall to the ground and be deactivated until it is thrown again.  While it is in motion, however, it cannot be stopped.