R'lyeh, the Sunken City

Cumulative upkeep - Tap an untapped creature
you control.
Whenever a creature attacks you or a
planeswalker you control, that creature's
controller gets an investigation counter.
Whenever a creature deals combat damage to
you, put that many madness counters on it.
Partner with Cthulhu, Eldritch Horror
R'lyeh, the Sunken City can be your commander.