the old echo nuker was just have arcane echo and then use meteor shower or fire storm.
hows about:
Arcane Echo
Echo {E}
Fire Attunement
Meteor Shower (or whatever)
the rest can be what ever you want.

first cast fire attunement, then echo arcane echo. cast your new arcane echo then cast Meteor Shower. then cast the origional arcane echo (shouldn't be far from recharging) and cast the echo, arcane echoed Meteor shower. then cast the newly arcane echoed Meteor shower.
this should work... just leave about 10 secs between the echos and the showers to allow the first echo to recharge. and you can put out 3 meteor showers in 35 seconds
'course the exhaustion will be almost crippling. but then i don't think even glint could survive this.
will it work though? i don't have the nececcary characters to try it out.
(it looks very complicated so good luck understanding it)