Clarion Of Mind Fire

—This spell can't be countered
Flying, Mindburn 3 (Whenever this creature
becomes the target of a spell or ability, exile the
top three cards of that player's library. They may
take damage equal to the exiled cards converted
mana cost. If they don't, counter the spell or ability.)
At the beginning of each endstep, if an
opponent took damage this turn, draw
three cards and discard a card.