WAD or arrows to move. Space to use nail. Q to vengeful spirit. F to heal a mask (just press f, and it will heal itself.). C to dash. H to show enemy's health. Charm code can be typed in any game of HK:TCoA series.
Thanks to @Spykir for boss idea! "Hollow Knight: The cost of art" team: @HollowKnightGuy - the publisher, codemaker and artist (and me). @GrimmUltra - the statsmaker. Credits to Team Cherry! Don't even think about tiping the game's name in charm code section!
