The Carriage of Madness

When The Carriage of Madness enters the battlefield, create a 0/0 black Nightmare creature
token, then put +1/+1 counters on it equal to the number of life you lost this turn.
Whenever a creature crews The Carriage of
Madness, put a +1/+1 counter on that creature.
Crew 4, The Carriage of Madness can be your commander