MTG Salvation

Cards that can counter atraxa strategy or cards that are good against planeswalkers in general.

Solemnity

• Hex Parasite
  
• Sword of Sinew and Steel
  
• Magmaquake
  
• Archon of Valor's Reach
  
• Breya, Etherium Shaper
  
• Casualties of War
  

Creatures. The combat step.

I had a super-tuned $10k planeswalker deck for a long time and while it was fun, it always fell apart when aggression happened.

Zealous Conscripts. It can kill 2 planeswalkers sometimes.

Agent of Treachery is great when their planeswalker is about to ult. Also, while the new Vorinclex, Monstrous Raider is good with planeswalkers, his second ability is good against them as well. Finally, as Cranky said earlier, planeswalkers fold to aggression.

Spectral Procession or other ways to create multiple flying creatures.