Collecting the indicated number of Golden Scarabs to get the bonus at 
Muramasa's shop. Note: You cannot collect Golden Scarabs when playing as Rachel.

Armlet of Benediction     : 30 Golden Scarabs
Armlet of Celerity        : 25 Golden Scarabs
Armlet of Fortune         : 40 Golden Scarabs
Armlet of Potency         :  5 Golden Scarabs
Dabilahro                 : 20 Golden Scarabs
Great Spirit Elixir       : 35 Golden Scarabs
Jewel of the Demon Seal   : 45 Golden Scarabs
Life of Gods              :  1 Golden Scarab
Lives of the Thousand Gods: 10 Golden Scarabs
Plasma Saber MkII         : 50 Golden Scarabs
Spirit of the Devils      : 15 Golden Scarabs