Very intresting and rather unique card. Rather due to GotP, but this is a nice idea too. Only thing I don't like: why does a Juggernaut affect discarding?
I therefore suggest another name: Inevitable
EDIT: Why does it fit better? Because that name is actually tied with its ability, if you think about it. Also, Ghost of Inevitability might be good too.
EDIT II: Also, take into account the rather likely possibility of a turn 2 creature with 8 attack... At the cost of one card. Novabows that get lucky can have the same effect for 4 (3 Nova and a Grabby).
Because a juggernaut originated in English as a humongous humongous, even if you try to throw it away? Or maybe throwing it forward is the impetus to send it rolling? Or maybe it's from the colloquial term "juggernaut" to refer to a force that is mercilessly destructive and unstoppable? Or maybe it's from the literary term "juggernaut" used in the mid-19th century used to describe, for example, Hyde, who succumbed to blind devotion and merciless sacrifice?
I don't see how the adjective "inevitable" better represents summoning something by discarding it.
Sure, it's a turn one creature, but that's sacrificing one turn of quanta generation (not playing pillars in your hand), and possibly 7 cards (what you don't play to discard juggernaut)