The Magister

Ward-Create a Sanction token. (It's an artifact
with "Law-When you cast your first spell each
turn, tap an untapped artifact or creature you
control." and "Sacrifice this artifact: break the
law.")
When an opponent breaks the law, you may
create a 1/1 white Soldier creature token. Put
X +1/+1 counters on it, where X is the number
of times that opponent has broken the law this
turn. This ability triggers only once each turn.