The only thing I would change of AST

[DarkmoonVael]

Yeah, I can't agree more with you. It's a final spell that has 2 minutes CD.. and all it does is stun enemies for 4 sec and extend buff for 5 seconds. Well, I don't think they should add anything except reduce CD. I can see SE taking this approach actually..

But if you want to see Assize like effect.. If I were to design this spell: Celestial Opposition: Stuns all enemies for 4 seconds. Additional effect: Bestow shield to all nearby allies +15% HP (stack with other shields)
Additional effect: HoT 150 potency for 4 sec.
Additional effect: DoT 150 potency for 4 sec.

HoTs and DoTs ticks once every 3 secs. Any HoT/DoT duration that isnt divisible by 3 has superfluous duration on it.