Pokémon Model Ripping Project

[sum1]

Ok, Blender just doesn't seem to work well with anything. The meshes of the SPICA models break apart from each other during animation; showing visible gaps between them. Joining the meshes stops the breaking, but the model still distorts itself weirdly; most noticeable is squishing of the head & face. Same problems with all the SPICA models that I tried. I wonder if it's an issue with parenting; because the meshes weren't parented to the armature when first imported. 
None of these problems occur in Unity.

Hat Pikachu Breaking:



Rockruff head squishing:






(I still need to figure out eyes/mouth)