Lets set up with the basics: When you get to the this slot in a Collector Booster, youre going to get a Showcase (In this set, thats the Monster Manual), Borderless, or Extended-Art treatment in foil
Dark Ritual Generating 3 mana for the cost of 1 seems innocuous at first, and Dark Ritual is card disadvantage
You could force something to block Nemesis, or cycle a Jund Sojourners, or sacrifice a Goblin Arsonist
If you're struggling with creatures that have Protection from Red, this also helps there, but those applications aren't going to come up quite as often
While itll take some reps to understand where and when you can go off, the how is relatively easy: make a bunch of mana with rituals, cast cantrips to run up the storm count, mix in a Past in Flames, and then put a lethal number of Grapeshot copies on the stack
Brokers Charm has three modes that are always relevant in EDH