No Canon or Yongnuo flash can simultaneously be used as a slave and a master. It has to be one or the other. The way the YN-568EXII is tripping the 430EXII is via a series of optical light pulses--as a wireless TTL master it can communicate a ton of stuff aside from the fire signal. But it can only do that if it receives additional signals from the camera hotshoe.
Your Ares triggers are manual-only (easy to tell, because it only has the single contact on it). It can only communicate the "sync" (fire) signal between the camera and the flash. All the wireless commanding, TTL, or HSS signalling is done on the other four pins of the flash foot--which can't be communicated by the Ares triggers. So they can't fake being the camera hotshoe. And the YN-568EXII never receives the signals to send all the master signaling to trip the 430EXII as a slave.
My best advice is to buy another Ares receiver unit for the 430EXII. Getting another YN-568EXII won't solve the issue.
It's generally difficult to mix manual radio and optical TTL systems together for wireless flash triggering. You should generally stick to one system or the other. If you want all the "goodies" of TTL/HSS, etc. over radio, then consider moving to the Phottix Odins/Stratto TTLs or the Yongnuo YN-622C triggering systems instead.
