Complex sentence: The album was released without Game's verse since he was at the height of his feud with 50 Cent; if anyone collaborated with an artist 50 Cent was feuding with, he would start feuding with that artist as well.
Split into simpler sentences: The album was released without Game's verse since he was at the height of his feud with 50 Cent. At that time, if anyone collaborated with an artist 50 Cent was feuding with, he would start feuding with that artist as well.