SC2Mapster

Hi, I'm currently working on an ability that when casted, the effect will be randomly appearing 360 degrees around the caster (with caster in center). The approach I used so far is similar to the Odin barrage ability, where I also use a variancer to randomize the actor controlling the effect from appearing. However, the model actor is not appearing at all, but the damage effect is. So I'm guessing the problem is with the SOp. I've tried Source Point, Caster Point and the model isnt showing up still. (The Odin Barrage ability uses target point, but since my ability is instant, there wont be a select target cursor) Which site of operations (effect) should I use to let the actor controlling the model appear within a circle radius around the caster 360 degrees? And how do I control/adjust the radius of how wide the circle of effect should appear within? Any help is greatly appreciated. Thanks in advance:)