MArcomage

I would suggest to change title to something more appropriate.

Maybe "Hatred".

Also, because it is rare, it should do something in the other case (no keyword card in matching position), or make it uncommon and rebalance it.

Changed name to Purge.

And i think it's fine with only keyword matching condition, cause there are plenty of conditional cards, which can be useless.

What does it do when there is more than one keyword? Random? Greatest number? Any and all?

I'd want to put "if not New" on here to give the opponent a chance, especially with existing options to shuffle a hand or swap targeted positions.

If multiple keywords - then all of those are discarded. And from both hands.