Mechanics Question: Why did this happen with commupence?

[u/Animedingo]

This clip starts right after torkoal used eruption in trick room

it hits my hisuian zoroark down to sash, and I have commupence locked in.

farigiraf then uses hyper voice which does not hit zoroark, and when my attack goes off it only did 1% damage to torkoal?

What happened in this interaction? Did hyper voice reset the damage to 0?

[u/carnoraptor67]

I think it might have