I believe Particular would be good for this effect of taking a frame of black and it's numbers that begin wiping away the black, revealing a scene. I can't get my head around how to achieve this in Particualr. I have succeeded in creating a very "layered" comp utilizing the numbers effect on each layer. It's alright, but I don't have the look I want, and I don't have total control of the look. anyway.
I'm trying to have so many (black colored) animated numbers that they make the frame totally black by overlapping, etc, then the numbers either decay or scale down or count down to wipe away the black revealing the next "scene". Did you get to see that image file showing a basic representation of the look?
I don't think you will get it working this way. Undoubtedly from my POV another trick needs to be employed which is expanding/ shrinking the numbers' contours using e.g. the Simple Choker effect. Actually it's just a matter of structuring the project properly.
a) Create the moving numbers in a separate comp.
b) Put that numbers pre-comp in a second comp. Apply the Simple Chocker and animate its parameters so your comp changes from discernible numbers to a solid area. Use a feathered linear wipe and animate it in sync with the Choker.
c) Use that Choker comp in your main comp as an Alpha matte/ Luma Matte.
There are other ways to approach this, but this is the simplest and most efficient one IMHO.