What do you mean, “Without masking and all of that business”?
How do you propose creating a shadow?
You could create your shadow by casting a shadow by using 3d layers and lights. You’d have to either animate the light or the layer that’s casting the shadow. (Or both.)
You can also use a layer (masked or not) as a track matte for an adjustment layer with levels and/or curves applied (or a black solid).
This tutorial on shadows may help or possibly this one.
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(The ‘Great’ stands for ‘Not So Great, in fact, Extremely Humble’)
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