Unity animator only works from parent object?

Here are 2 problems.

1. Animator only works at parent object? I tried to move animator component to child object that has mesh renderer, but when I do it, animations are not played like this video.

2. Above 1. 's trial intention is eventually sync mesh collider to this monster 3d model's animation. So trying to achieve monster hit user's character when it attack right timing.

But as you can see, mesh collider stand still regardless with current playing animation.

How to sync these?

Thanks.

 

I've used this asset before in a similar situation: https://assetstore.unity.com/packages/tools/physics/rascal-skinned-mesh-collider-134833?aid=1101lGst

Or maybe instead of a mesh collider, just use box colliders on each bone to approximate it.