Sparksteel the engineer

When Sparksteel the engineer entre the battelfield, look at the top four cards of your
library. You may reveal an artifact card from
among them and put it into your hand. Put the
rest on the bottom of your library in a random
order.
Whenever one or more artifacts enter the battelfield under your control, put +1/+1 conter
on Sparksteel the engineer.This ability triggers
only one each turn