Well, clearly, by emulating the card art
However his three toughness puts him well in range of most removal, so he's not at risk of becoming a Sheoldred-style threat that you have to tech around
The casting cost makes Keg available to everyone and gives otherwise slow strategies a fighting chance against rushes without having to sacrifice
Chandra gives us a straight reprint of Chandra, Torch of Defiance|FRA alongside her chilling mirror, Chandra, Chill of Compliance|FRA an ice mage with eerily similar abilities
On top of everything else, being a creature lets you utilize Venser a lot more than a regular instant, either by flickering or recurring it from the graveyard
Medallions Rocks that ramp for two mana are big game