"In \"The Flying School\", Riven receives the boomerang. In \"The Golden Auditorium\", Riven is seen training with his boomerang."@en . . "In \"The Flying School\", Riven receives the boomerang. In \"The Golden Auditorium\", Riven is seen training with his boomerang."@en . . . "Solar Boomerang"@en . . . . . . .