When there are characters on the field whose combined cost is 5 or higher, he can look at his top Life card and play it if it's a Supernova character
Add to that the possibility that itll gain either double strike or menace each time it attacks and this is a card I could see having a place in a deck that doesnt care about coin flips specifically
Bonehoard Dracosaur Giant 5 mana dragons come and go, but usually they need haste to make it in Standard
Here's are some prerelease kits that contain codes
At this point, Ugin became one with the realm in order to seal Nicol Bolas there
They can't be the target of spells or abilities, their static abilities have no effect on the game, their triggered abilities can't trigger, they can't attack or block, and so on