Khanrizach, Soul Harper

Menace
When Khanrizach enters the battlefield, mill 2
cards and amass Necrons 2. (To amass Necrons 2,
put 2 +1/+1 counters on an Army you control. It's
also a Necron. If you don't control an Army, create a
0/0 black Necron Army artifact creature token first.)
{b}{b}, {t}, Sacrifice Khanrizach: Return another
target artifact from your graveyard to the battlefield tapped under your control.