I guess the ability to flash this in on your opponent's end step, kill a blocker, and then hopefully defeat the battle could be powerful, although this still requires dealing five damage to remove the defense counters
Brawl Not Legal Vintage Legal Timeless Not Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Not Legal Toolbox Buy This Card Notes and Rules Information for Espers to Magicite: You don't choose a target for Espers to Magicite at the time you cast it
If I were to make a sliver Commander deck, this would be my choice of commander
Heroic Intervention, Teferis Protection, Akromas Will and Clever Concealment provide an excellent core protection package
A build probably exists that has a mill plan meshed together with a ramp into Ulamog, the Ceaseless Hunger plan
If left around too long, they can amplify a Commander decks capabilities, taking over the game