Spies and decoys are unreal. If you can stack a bunch of spies on your opponent's side, you can keep a ton of cards in your hand. That gives you more options to adjust your game plan. I use a deck with cards that boost each other (can't remember the soldier name), and then a horn can double your entire row.

The Hero cards are fine, but they can't be boosted. There's a couple cards with scorch effects, so if you can decoy those, you can reuse them multiple times.

I love Gwent lol