Picked up one of those greater element documents and I'm planning on adding some flares to my warmage's lance. The question is, which element?

I'm leaning toward fire because it's fun in troll warcamps. The problem with fire, of course, is that it won't work on everything. Any thoughts?

My mage is attuned air. I'm wondering if void flares would work in conjunction with 502? Or is that just with an ebladed weapon?