I have a small question regarding CATegory scaling of powers. Blast says that it's strength scales with CAT. Does the strength of powers like Severance or Fury also scale with CAT regarding the rules of category difference, or only the size/area part of those powers gets scaled up? If I try to cut a fly-sized category 7 sin with a CAT 1 Severance power, does it become impossible (more than 3 categories higher) or is it a normal/advantageous roll (heavy furniture size vs fly size)?
I think that generally size of sin scales with CAT. obviously subject to Admin discretion, so you can definitely have a fly-sized cat-7 sin.
But if you have a cat-7 sin with the size of a fly it will still have durability commensurate with CAT. considering cat-7 is durable enough to make a cat-4 attack (size/destruction on par with a large vehicle) ineffective it seems that no cat-1 attack, regardless of relative size, will be effective. You could play it as strength of psychic phenomena.
Going from the media that inspired CAIN, for example JJK: Gojo (arguably cat-7) can no-sell / tank any sort of attack because it can't hit him or make an impact on his Limitless defenses. It doesn't matter if a cat-1 attack is bigger than him, since his phenomena make it impossible to make a lasting impact in the first place.
A little rambling, but hope this helps. The lack of hard rules wrt power scaling make CAIN really interesting in this respect. Narrative obviously more impactful than hard stat sheets.