While there are probably some small upgrades that can be made to the mono-blue build, like additional copies of Castle Vantress, to really improve the deck's weaknesses, we need to move into a second color for hard removal and sweepers
Although Fact or Fiction is the more powerful draw spell it can be dangerous in a 40 card threat light control deck and is also a spell you can't do anything with before you hit four mana
Akroma, Angel of Fury Sure, Akroma, Angel of Fury is a high mana cost commander, but protection from white and blue can be integral for an aggro strategy
I want to cast big instant/sorcery spells and copy them
But with the ability to pay 1 mana and sacrifice it, you can intimidate and derail your opponents plans
As a three-mana creature, theres nothing super-exciting about Phyrexian Dragon Engine