"PREY"? Species 8472 has a weird language, Janeway tells Seven her story about the Cardassian, and we didn't see the Hirogen do any experiments on their prey.
Got it! Clue 1) The musical language is very unusual. Clue 2) Being in an alliance makes Janeway nostalgic for the Federation. Clue 3) Reference to the starless void in Where Silence Has Lease in which weird experiments were performed. Clue 4) They stick to their principles in the void instead of conforming to what everyone else is doing and raiding ships for their supplies. Clue 5) They ally with people they find out raided other ships to murder them.
Next clue: A surrealistic remark (though it may be a little too cryptic so I'll add) and a belated homage.