If you're not getting what Daffa means from the SetUnitProp, although it is quite simply maybe you don't have not spent enough time here learning. So, we'll use Rheiko's suggestion and use Channel.
I also changed the special effect to be "on" the unit, just in case you didn't know, if you attach the special effect to the unit, it will "follow it". Which is why I think you wanted to pause the unit. You don't need to though, to test use this test map and just turn off the "Add "Pause" ability and "Order unit to cast" and attack the unit you cast on and watch it follow the unit. I also changed the targets so you can cast on yourself to see how the pseudo pause works atm.
Questions or concerns just msg back.