Then:
-Variables:
-Real = facing of triggering unit
-Point1 = targeted point of ability being cast offset by 1000 facing Real
-Point2 = position of triggering unit
-Actions:
-Create 1 dummy at Poin2...
-add ~1 second expiration timer to last created unit
-order last created unit to move to point1
-clear leaks
But note that maximum unit speed is 522, so if you want dummy to be faster you'll need periodic trigger (that 0.03 thing) that moves dummy.
Or you can simply make another shockwave with 0 damage and with different model, and dthe dummy casts it right after you cast the main one.