Complex sentence: With so many secrets already, even more are being revealed--for instance, Bluestar is the mother of the RiverClan warriors Mistyfoot and Stonefur, and her mate was Oakheart, the former RiverClan deputy.
Split into simpler sentences: With so many secrets already, even more are being revealed. For instance, Bluestar is the mother of the RiverClan warriors Mistyfoot and Stonefur, and her mate was Oakheart, the former RiverClan deputy.