Kog'maw Damage bug

So the last game i played against a kog and his damage was far beyond anything ive seen at level 7, He had a rageblade,boots,and dorans blade and was able to 3 auto attack me and my jhin with only using arcane bio 1v2. I was playing thresh used my W shielded both of us and still got 3 shotted by the kog who at the time was 0-2-1