Lord Metalsmith

First Strike, Improvise, Indestructible, Trample
Lord Metalsmith cannot be blocked by creatures
with a power less than half of Lord Metalsmith's
power.
When Lord Metalsmith enters the battlefield all artifact creatures get a +X/+X.
Whenever an artifact creature enters the battlefield, Lord Metalsmith gets +X/+X.
{1}{t}: Create a 1/1 Metal Human with haste.
Untap Lord Metalsmith. You can only do this
once per turn.