20 minutes of a screaming man who sounds like he's on fire, I'd probably introduce them to North, an Arizona-centered band that does post-metal extremely well, but throws in touches of Mono or Explosions in the Sky to lighten the intensity a bit. The contrast between melodic portions and the heavy intensity that truly makes the band is what's beautiful about post-metal, and it's not hard to find a track in North's discography that really means something on a full spectrum of emotions, ranging from anger and hatred to a tender reminiscence.
North's first couple of EPs, Siberia and Ruins, were both purely instrumental, completely phasing out the need for screams at all, and were the lighter side of their discography - without a metal vocalist, they were able to focus on changing how their listeners were feeling while listening to their songs, and as such, there were some deep, melodic chordal changes, such as with Siberia's "Depleted and Ill-Willed" or Ruins' "Nex In March." Those songs have a central post-rock feel, but do dabble towards metal a bit, instead of being heavily focused on the darker side of music.
When North progressed onto their first full-length, however, things progressed, their sound evolved, and they added a vocalist. The result was explosive; tracks like "I Am Become Death" and "Eidolon" transformed their sound completely, and What You Were is an easy alternate pick between around the area of Russian Circles or Pelican, due it being extremely catchy and melodic, but also conforming to the post-metal norm much more than their experimental EPs. With The Great Silence, they move in a more experimental phase, with Ty Engle leaving the band, their sound becoming much more progressive, much more vocal oriented (as opposed to using vocals as layers, or background noise), and a lot of progression on the more grandiose soundscapes of their music. The layers sound beautifully complex and echoic, but their breakdowns suffer a bit for it - they almost lean towards a Mastodon-esque filler whenever they begin chugging away, and that's a little too progressive for the band I've come to know and love as a post-metal band. Still, though, The Great Silence doesn't disappoint as a sophomore album, and it's definitely worth a listen. So, if you need something new to add to your post-metal library, look no further: North is here, North is bad, and North will fuck your shit up.
You can find all of their recorded EPs and full lengths on their Bandcamp.