Shockwave, Cold Strategist

More Than Meets The Eye {1}{w}{u}{b}{r}

Whenever another legendary artifact creature you
control converts or enters the battlefield, choose one
that hasn't been chosen this turn. After this ability triggers for every third time, convert Shockwave.
•Deal X damage to any target where X is the mana
value of the creature that triggered this ability.
•Put two +1/+1 counters on target artifact.
•Draw a card.