From my experiance editing units, there is a specific line for splash radius, although, I have no experiance with items that generate extra attacks. So I popped your AOS map open because I remember a phoenix attack item in it. Maybe you could try to add a buff to the ability for the item, or if you want it to attack multiple targets, you could just give it a multi-shot effect.
I think u should just make a 'copy' of phoenix fire. just make dummys with 0.5 cooldown, no model and model size 1. thn if some1 has the item make some dummys at the position of the unit with the item. (also make a trigger that moves the dummys to the unit every 0.1 sec)
You could always to the simple thing and give it multiple phoenix fires. Sometimes just giving it phoenix fire several times doesn't work so create custim ability phoenix fire but change nothing (unless you really want to) It worked for me when i made a my hero so yeah...
Well I know I can give it more than one attack but because its used as an item(like in battleships) I can only have at most 4 on one item at a time and anyway thats not the affect I wanted at all, all I want is for it to have a splash attack. You would think this would be a simple thing but apperenty it is not. But I'm still looking for help on this if any knows how to do it.
just like I said, u'll have to make dummys without model, scaling 1 and a ranged attack with missle u want. then if unit acuires an item, set 'itemunit' (unit variable) = hero manipulating item and create some dummys at the hero
then another trigger that moves the dummys every 0.1 sec to the 'itemunit'