the synth at the start... 3rd bar. can't miss it.Not sure what sound you're talking about but man this track was dope and I usually hate his stuff lol.
Nexus or Sylenth1... Go through the pad presets on that and you'll find it... Sounds like a saw wave going through a filter with a lfo modulating the cutoff... just look for swell pad presets and recreate them with your own taste..