Arials, being the masters of the air with their wings should answer to no one when flying except perhaps other arial and air form majors.

That being the case, a potential inherent skill that an arial could have would be to force other flying creatures to the ground through a series of swoops and what not with their wings.

Effect: Flying creatures, PCs, etc that are not arial or air forms are effectively earthbound for 0 hours in combat. This would not cancel flight, and flight would resume once the 0 hour ticked by, but it would keep the person near the ground until they can get clear of the arial.

Restrictions: Can be done multiple times, but only once per hour. Cost of significant movement in order to perform, and lag enough so that the following wouldn't be possible for say, an arial thief on his lonesome:

inherent 'force down' Billybob
trip Billybob
<- insert kick to head here.
trip Billybob
<- insert kick to head here.

Billybob = Dead

Flame away