Hello! Thanks for your support.
Depending on the pack you downloaded from the store, some of them could appear blurry if they are scaled up too much.
It's the case for Elemental Packs 1, 2 & 3 since these are ports from MV to MZ. The original files were originally created to be used in RPG Maker MV, that is why the resolution is low(192x192 per frame).