TI'm not sure why you are having an issue. Giving the Immortal a placement footprint should not prevent it from moving.
Edit: sorry, I didn't read it correctly. I see that you want to give it the ability to move after a certain duration. You could use a morph like the spine crawler, but an easier way would just be with triggers or with a behavior. You can easily adjust a unit's movement speed with the "Set Unit Property" action.
@chickenballs02: Go
TI'm not sure why you are having an issue. Giving the Immortal a placement footprint should not prevent it from moving.
Edit: sorry, I didn't read it correctly. I see that you want to give it the ability to move after a certain duration. You could use a morph like the spine crawler, but an easier way would just be with triggers or with a behavior. You can easily adjust a unit's movement speed with the "Set Unit Property" action.