Edison Format · March 2010
You can Tribute a face-down Alien to activate "Planet Pollutant Virus".
Placing A-Counters on monsters does not start a chain.
If 2 copies of "Planet Pollutant Virus" are active, their effects are both applied, so each monster Summoned by your opponent gets 2 A-Counters.
You can activate "Planet Pollutant Virus" even if your opponent controls no monsters, or controls only monsters with A-Counters.