Photon Boosters are only available online by trading photon drops in the gallon's shop quest. Here's the link to the trade-in guide: http://www.ragol.co.uk/guides/EplVlFZVEkMOqDFddf.shtml
All they can be used for is to combine with either the Flame Visit, Frozen Shooter, Panzer Faust or Maser Beam to make the stronger variation of each (Burning Visit, Snow Queen, Power Maser or Iron Faust). That's all they're good for.
All they can be used for is to combine with either the Flame Visit, Frozen Shooter, Panzer Faust or Maser Beam to make the stronger variation of each (Burning Visit, Snow Queen, Power Maser or Iron Faust). That's all they're good for.