To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions
The idea is that by putting all the Grim Haruspex effects together, you should discover plenty of cards you werent aware of for your decks, especially considering singleton formats like EDH which benefit from redundancy
The recipe gets real when you mix in artifact sacrifice payoffs like Crime Novelist, Scrap Trawler, Prized Statue, Ichor Wellspring, and Weapons Manufacturing
I mentioned Drop of Honey in the green article in this series
For example, if you haven't drawn any cards yet during a turn and cast a spell that instructs you to draw three cards, you'll draw them one at a time
One mythic can flood you with mana, bury your opponent in card advantage, and threaten to end the game on the same turn