An effect that changes icons

Want to make this work? [object]

   name= _ "Flaming Sword"
   image=items/flame-sword.png
   description= _ "This sword deals 50% more damage than other swords and deals fire damage."
   [effect]
       apply_to=attack
       name=sword
       set_type=fire
       increase_damage=50%
       set_icon=attacks/sword-flaming.png
   [/effect]

[/object]

Place this macro after that the unit takes the object, and also in a global post advance event (in all scenarios, for all units who might have their attack icons altered).

define UPDATE_ICONS

   #It searches through all the effects of all the items, looking for a set_icon tag.
   #When it finds one, it finds all attacks with the same name as the name that the
   #attack affects, and changes their icons. This works only until the next advancement,
   #then it has to be reapplied. It might check for other properties of the attack filter
   #of the unit, just needs a little bit of tweaking.
   [store_unit]
       [filter]
           x,y=$x1,$y1
       [/filter]
       variable=advanced
       kill=no
   [/store_unit]
   {FOREACH advanced.modifications.object i}
       {FOREACH advanced.modifications.object[$i].effect j}
           [if]
               [variable]
                   name=advanced.modifications.object[$i].effect[$j].set_icon
                   contains="png"
               [/variable]
               [then]
                   {VARIABLE attack_name $advanced.modifications.object[$i].effect[$j].name}
                   {FOREACH advanced.attack k}
                       [if]
                           [variable]
                               name=advanced.attack[$k].name
                               equals=$attack_name
                           [/variable]
                           [then]
                               {VARIABLE advanced.attack[$k].icon $advanced.modifications.object[$i].effect[$j].set_icon}
                           [/then]
                       [/if]
                   {NEXT k}
               [/then]
           [/if]
       {NEXT j}
   {NEXT i}
   [unstore_unit]
       variable=advanced
       find_vacant=no
   [/unstore_unit]
   {CLEAR_VARIABLE advanced}

enddef