For some reason MTG Final Fantasy appears to be the set for surprisingly large numbers
A great creature with Panharmonicon is Yarok, the Desecrated, a popular commander that functionally does the same thing but triggers every enter the battlefield of all permanents instead.
Creative Energy is led by Satya, Aetherflux GeniusSatya, Aetherflux Genius, a 3/5 Human Artificer with menace and haste
And given power/toughness in magic are pretty uncorrelated to how big a creature is at this point, it's just kind of, there
He would be overpowered if he actually had a potentially game ending ultimate
By offering your opponents gifts for doing your dirty work, you can control the pace of the game without being perceived as the primary threat