This rather flamboyant member of the Monarch Flycatcher family (Monarchidae) is highly dimorphic with females and juveniles such as this appearing quite different from the all black males. I believe this is a juvenile based on the buffy wash across the breast. Seven or eight subspecies have been described differing in measurements and mantle color of the females. Based on range, this is the long-winged M. a. chalybeocephala whose name comes from the Greek meaning "Steelhead." Canon PowerShot SX60.
References:
Gregory, P. (2017) Birds of New Guinea, Including Bismarck Archipelago and Boughainville. Lynx Edicions, Barcelona.
Gregory, P. (2019). Shining Flycatcher (Myiagra alecto). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/59264 on 1 November 2019).