You can cast Counterspell without a spell slot. If the target fails its saving throw against this spell, it takes 4d8 Force damage. Intelligence, Wisdom, or Charisma is your spellcasting ability for this spell when you cast it with this feature (choose the ability when you cast the spell).
Once you use this feature to cast this spell, you can't do so again until you finish a Short or Long Rest. You can also restore your use of it by expending a use of your ValdaSpire24 (no action required).