Well, I can't quite see how it's OP yet. If the card is used early, then both players are left to stall. If played later on, both players can have ample amounts quanta by then, for a rush. Simple, very common ways can be used to get around this: quanta generating creatures like Ray of Light, spells like Supernova, or even playing in upgraded Towers. Several CCs can be implemented as well, alongside the poisoning: Freeze stops abilities upon use but allows poison to continue, Shockwave can be coupled with it as well, Lightning is even in the same element, Quint to keep the creature from healing again, Oty can meet it in the middle as he grows while the target creature's HP drops.