404, Terrorizing Nightmare

When 404 enters the battlefield, exile target card
made on mtgcardsmith. If that creatures
controller made that card, laugh at them, then
search your library for a card you made on mtgcardsmith, show it to them and put it into
your hand.
Each time you encounter a 404 error on mtgcardsmith, put a +1/+1 counter on this
creature. You can't do this more than once each
turn, unless you are unlucky.