Deals damage, ignores most abilities and its category depends on whether the user's Attack or Special Attack is higher

Photon Geyser deals damage and its category depends on whether the user's Attack or Special Attack is higher.
If the Special Attack is higher, it becomes a Special category move, otherwise it is Physical.
Photon Geyser ignores most abilities while attacking. The list of ignorable abilities is the same as Sunsteel Strike.
Photon Geyser only considers stat stages for which stat is higher and ignores all other stat changing effects such as choice items or abilities.

• In
  SM
  this move does not exist in the game data and no Pokémon that know this move can be transferred to one of these games from another game or the Pokémon Bank.
  This is fixable by making the Pokémon forget the move beforehand.
• In
  BDSP
  and from Gen 9 onwards this move is not selectable in battle.