Youll be taking two or three extra turns on average with five coin flips
So long as they continue to print absurdly good monsters at the very top end cards like this that can abuse mana costs will be cube worthy, despite not being guaranteed to be fun for all players

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It gives you good graveyard filling potential, it lets you get things out of your hand in a controlled way, it is still useful if milled directly into the bin and it is super cheap letting you get into things right away
For each creature that dies this way, you create a 1/1 Slug creature token
As a side effect, these also typically extend the length of Commander/EDH games by 20 minutes