Poison deck help

I'm thinking about building an Elden Ring proxy deck (after watching this video), and this Atraxa I made would be a fun proxy commander for a poison deck. Do you have any deck recommendations or tips for building a deck that's not too toxic to play against and suitable for casual commander?

Alternatively, a -1/-1 counter deck would also be fun if that's a thing that exists (it doesn't have to be op).