In a deck where youre trying to tutor up legendaries anyway, getting more reach in that department is huge
I can certainly see cutting some of the more high powered, or low powered, cards to adjust the power level of the stack accordingly
Going first is often dangerous in this format, because that player is barred from using Trainers or Supporters, leaving them stuck with what will usually be 1 or 2 low-HP, evolving Basics, and few options for setting up
This card can be especially nasty in Commander, where creatures run rampant and playing control strategies often dont go all that well
Revealed by Bleeding Cool on September 4, Secret Identity is a one mana spell that lets you temporarily turn a creature into a 1/1 Civilian with hexproof or a 3/4 hero with flying and vigilance