Karn, Artifactual Creator

+1: Create a 3/3 colorless Golem artifact creature token with indestructible. Draw a card if you control 3 or more artifacts.
-2: Create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."
-12: You get an emblem with: "Whenever an artifact enters the battlefield under your control, draw a card."