Culling Ritual is a rather popular Commander board wipe at more competitive tables
Hall of Mirrors affects only creatures you control at the time its ability resolves
Fast mana from Sol Ring, Ancient Tomb, Skirk Prospector, and Jeska's Will help you to cast key pieces early, while Lightning Greaves, Swiftfoot Boots, and Thousand-Year Elixir make sure that Krenko can tap right away and survive removal
Or, you know, one Akroma Angel of Wrath in the bin
The designers had to create a Wizard leader that meaningfully supports all the different types of Wizards in Grixis colors, from the classics like Venser, Shaper Savant and Snapcaster Mage to the weirder stuff like Magus of the Will
Its a weak creature and very limited in what it does, since you won't often be able to play cards your opponents made you discard