It has 3/4 power and toughness, deathtouch, and a Ward cost of "Get five poison counters." Its final line of text is a triggered ability that reads: "Whenever another creature you control with deathtouch dies, each opponent sacrifices a nontoken creature of their choice." Poison counters, which debuted in 1994s Legends set, are a mechanic that accumulates on a player rather than anything on the battlefield
Without the opponents cooperation, you have to do the work yourself with Ingest creatures, which seems like a pretty low power-level and worth avoiding in Constructed
This Dragon's monstrosity effect is costly, but in return, Stormbreath Dragon becomes a sizeable 7/7, and it deals damage to all opponents to keep the pressure up
Balance Think of the following scenario: I cast some mana rocks, have only Balance in my hand, and cast it
But its still going to be really strong late in the game
The curve is dangerously good with Llanowar Elves on turn 1, and Forest + Mossborn Hydra on turn 2