4x Extripate seems like a good choice here.

A well time Duress/Thoughtseize followed by Extirpate can spell game over or throw the game in your favor.
In my MBC deck, my Stax matchups were won by my extirpates.

I have tried Dash Hopes and had some great late game luck with it.

I  also MD 3x Engineered Explosives to deal with Chalice at 1 or 2

Shawn~