In theory, it's a decent concept, but the fact of the matter is...
This thing pretty much is instant death for any deck that faces it.
Even if you decide to not rob your foe blind of any quanta left after playing due to the pillar lockdown, They only get quanta either every other turn or one every three turns.
Not to mention a deck reliant on it's shield suddenly has a shield every other turn or once per 3 turns.
On it's own, sure, it's fine, but it just massively boosts everything that pairs with it, to the point of being a no-brainer card pick, like trying to make a deck without creatures to give you an idea of the advantage Breakdown gives to a deck, it's like all decks without breakdown are instantly and horribly UP.
And that's assuming it doesn't stack with itself, if it does stack with itself, Elements the Game PvP would become 'Who draws their BreakDown first?' This thing is easily in the SoF category of OP, it sounds harmless, but in practice, it's power is horrifying.