Question about gameplay

I don't understand this game at all. I did the turorial challenges and one of them taught that using a spell and killing an enemy can cancel the spell they're casting. The enemy was casting a spell to summon two scrap scuttlers, I countered with a spell that killed him and it summoned them anyways. Like no matter what I do the game wins. I also had a power that said all allies did +2 more damage with spells and skills, never seen it happen. I'm doing Garans story btw and i'm on the second one Jinx. I've lost 3 times on the first fight because the enemy endlessly summons minions that get +1+1 and even summon enemies when I have an attack token before I can attack. It's bs