You want your instants and sorceries to be cheap in order to cast multiple per turn, and you want them to make up 35-40% of your deck
The second answer here regards the cards in the five-to-seven-mana slots, which give us the worst games in our blight-scape
This left white and green
There are only a handful of ways to remove specific cards from your opponents deck, most of which are known by the slang term capping or surgical-ing. These come from Jester's Cap and Surgical Extraction, though there are a few other cards that are similar

Rarity: C Cost: 3U Card Type: Instant Artist: Izzy Name: Inspiration Finish: Regular Card Number: 010/030 Set Name: Welcome Deck 2017 Related Products Inspiration - Foil 7th Edition [2001] NM, English 1 In Stock NM, English 1 In Stock NM, English 1 In Stock Inspiration 7th Edition [2001] LP, English 4 In Stock LP, English 4 In Stock LP, English 4 In Stock Inspiration 6th Edition [1999] LP, English 4 In Stock LP, English 4 In Stock LP, English 4 In Stock Inspiration 8th Edition [2003] LP, English 4 In Stock LP, English 4 In Stock LP, English 4 In Stock Inspiration Visions [1997] LP, English 4 In Stock LP, English 4 In Stock LP, English 4 In Stock Inspiration Return to Ravnica (2012) NM, English 4 In Stock NM, English 4 In Stock NM, English 4 In Stock Falkenrath Reaver Promo Singles: Unique and Miscellaneous NM, English 4 In Stock NM, English 4 In Stock NM, English 4 In Stock Drag Under Promo Singles: Unique and Miscellaneous LP, English 4 In Stock LP, English 4 In Stock LP, English 4 In Stock

Even in terms of Grandeur commanders, this one blows, since theres almost no interesting colorless instants and sorceries