Weapons

what kind of weapon type makes it so that your aimer is a circle and does splash dmg?

I don't believe any standard attack type gives you a circle unless you use Attack-Ground, and that's part of the Artillery or Artillery - Splash weapon types.

you can make an ability and enhance it with triggers....
really easy...
EDIT: in other words, u can fake the attack by making a dummy spell with the "circle" and picking every unit in that region and dealing them damage; while spawning some effect at the "target point of issued order"...