Bhosadpiller or Bhosdapiller is a funny/Derogatory word for the term Blackpiller. It is a term for those on Internet who have a tendency or habit to blackpill everyone. Blackpill here means, to make people believe that everything is over and no one can fix it.
The term Bhosadpiller can be used to make fun of Blackpillers and their pessimistic attitude.
Bhosdapill refers to the blabbery which some self proclaimed geniuses do on twitter who think there is no hope for tomorrow and everything ends when people don't listen to them. Basically, it is nihilism on steroids.