I wasn't that sure how to explain it but here's an example and me trying to break it down. Note that you can do things differently, everyone has their own way of adding impact frames.
If you want more examples of people using impact frames, the stickman community on drawn and other places are usually really good with effects like that, so I definitely recommend checking them out. Other people, like @Poxem on drawn, and SurusuruWo on toon, are great at it.
Hope this helps
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@emi noemi
@your_hoodie im always rightHoodie
@emi is never right about my aret, lmao but thanks @ToonKraft127 uwuToonKraft127
BIG MOOD-Also @emi is right uwu
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u are good no matter what ur using shush bean