He can throw out -1/-1 counters for the low price of your life and a creature, and you also get to draw a card
Not competitively, but I can see myself building a deck around Rubinia Soulsinger if I pull one in a dollar pack at my LGS

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Using data to understand which cards you should respect, how aggressively you should mulligan, and what matchups you should tech for is incredibly valuable.FreedomWaffle - cEDH Tournament Grinder & Coach Myself and the other titans have a bi-weekly pod, mostly durdling some casual games on our nights off from plunging the various planes into chaos
For competitive play, you need English cards for Western tournaments
Otherwise you start the infinite loop that ends in their defeat when you hit combat damage with the Starscape Cleric, or my personal favorite, put a dirt cheap dual land, Scoured Barrens or Forlorn Flats into play