Steelheart Hoplites

Steelheart Hoplites can block an additional creature each combat.
Metalize {2} ({2}, Exile target artifact you control:
This creature becomes an artifact in addition to its other types.)
As long as this creature is an artifact, it has vigilance and "Whenever a creature an opponent controls dies, put a +1/+1 counter on Steelheart Hoplites."