MArcomage

Sawps 5N means "tower +5N, enemy tower -5N"?
Alternative phrasing:

discard from your hand all the cards also in enemy deck
tower +5N
enemy tower -5N
N = # of discarded card.

For balancing: 5N is too much, if enemy has a deck similar to yours you can have 5 or 6 enemy cards in your hand.
N should be capped or it should consider only cards from enemy hand (not deck)

I had trouble getting the card text short enough.

+7B cost, lowerd tower swap by 1

If I'm reading this right, perhaps "steal" in place of "swap" would better describe the effect while keeping it brief.

I don't really feel that either word fits perfectly when describing changes in height, but "steal" at least makes it more clear. "Swap" sounds like you're exchanging the heights like Wall Shift does.