I would assume - if possible - to make cones be like a wave - an expanding AOE.
That way we really have several unique AOEs
Bolt - Projectile - Travel until impact with solid object - Affects 1
Beam - Instant - Affect all within range
Ball - Instant - Drop-able with a radius AOE - Affects all in radius
Cloud - Persistent - Drop-able like a Ball but persists - Affects all in radius over duration
Wave [Tidal Wave] - Persistent - Drop-able Ball with expanding AOE - Affects all within new AOE
Cone [current] - Essentially a stretched Ball
Cone [proposed] - Expanding Wave [so we actually have 2 waves and 2 balls instead of 1 wave and 3 balls]
Well I think I can do this with a map effect, basically a cone shaped Tidal Wave, but then it would just be an expanding map effect and it really shouldn't effect targets in grids it's already 'passed over'.
If I can't get it to work it's no big deal though, it's not essential to the effect I just thought it might be neat.