J&K, the Aeons Torn

Flash, Flying
J&K, the Aeons Torn can't be countered.
When you cast J&K, take and extra turn.
When J&K enters the battlefield, counter target
spell and deal {x} damage to any number of creatures, planeswalkers, or players where {x} is
that spell's converted mana cost, then each
opponent discards that many cards.
Together, babe, we are unstoppable!