Ruling Omastar PK question

[Mewq]

lets say i have done 30 damage to a gyarados and then use pull down with my omastar does that kill the magikarp(who was a gyarados)?

 

[Chairman Kaga]

Yes. Once you finish resolving the attack (or anything else, for that matter), you KO check every Pokemon on the field. After the devolution, Magikarp has 0 HP left, so it's gone.

 

[Mewq]

thank u !