When playing a mission where one of the monsters in the top row is a Fallen, this disadvantages a strategy where you generate a lot of Blood in the early game. For example, you probably do not want to recruit a Barbarian before your first shuffle.
If you see Kami and an affordable unit with type "Ninja", consider a Ninja-based strategy. Kami becomes more affordable as you play various Ninjas. Therefore, you are designing a deck which will generate less Blood in the early game, and more in the late game. This way you will not spend the early game accidentally boosting the strength of the Fallen by generating too much Blood. Kami will help you eliminate the Fallen quickly enough to prevent it from embiggening itself too much.
Red Ninja seems a particularly potent combo in this scenario. Red Ninja is extremely inexpensive to recruit, so you can quickly make Kami cheaper to recruit. Also, Red Ninja insta-kills weak Monsters and generates no Blood at all, so it does not embiggen the Fallen.
Do you agree? What have you tried, and what worked?