SO just taking a look at the different mechanics of Keyforge and notice some silicate balance design in the game.
1st lets talk about offense or point scoring (what you need to win the game). Amber cards put points on the board bringing you closer to score those keys thus winning the game.
So how to stop Amber is the defense and that is reaping. Reaping is defensive as it denies amber your opponent needs to score out keys.
So the counter to Reap is Combat, reap holds amber it doesn't steal but if they get hit then all reaped amber is returned (unless otherwise stated). However While good combat counters reap it doesn't counter Amber as most amber is placed upon summoning.
So we got this Amber<Reap<Combat<Amber type balance here. Now when looking at your deck you need to chose which of your three factions are better at what. Next I will talk about how you should approach Keyforge like a coach in a football (NFL) game although it is a bit more like 2 (or more) ball football.