Simply put, in order for a card to be well-designed, it must have some sort of positive impact on the format , preferably at its time of release (though this is not a requirement)
#19 Gladions Final Battle Ultra Rare Gladion's Final Battle - 108/084 ME05: Pitch Black Ultra Rare Market Value Loading
It could be the story of a game of Magic itself, a full cinematic in one image with a dopey goose
Her owner, however, reacted out of fear and tried to destroy her by shattering her body and dropping her into a Boilerbilges furnace
Creating as many goblins as you can to fuel Krenko is key, from Dragon Fodder to Mogg War Marshal, combined with haste enablers, and effects to make sure they connect (like the flavourfully named Goblin War Drums)
Cyruss card effect is pretty straightforward