Yu-Gi-Oh! » Rulings Q&A

https://www.duelingbook.com/replay?id=384240-73454476

No, he has no effects. He is trying to add effects to Normal monsters.

Pretty sure "cheating" is a stretch here.

Their username checks out, they were trolling you...in an unrated match. (That is what it looked like to me)

So there's no reason to ban a cheater in non ranked.