[apocalypse80]

The "flying across the screen" doesn't require a shield.
Any attack of any mastery can do it , as long as the damage you do is far higher than the damage required to kill an opponent.

So I'm not so sure which attack you're looking for.

Shield smash , disable , pulverize , batter and shield charge all utilize the combined damage of your weapon and shield (and whatever bonus over that).
All of them are good ways to do a lot of damage.