Particle Cannon

If you chose Zarya, Energy accumulator as your commander or if Zarya is in your deck, begin the
game with Particle Cannon on the battlefield.
If Zarya is on the battlefield, she gains +X/+0,
where X is the number of charge counters on Particle Cannon.
Particle Cannon can hold no more than 10
charge counters on it at a time.
Remove 1 charge counter from Particle Cannon
at the beginning of each end step.