This space marine is going to be the sergeant for my Mark V armour plasma cannon heavy support squad. The bits come from a variety of sources. Most obviously, the majority of the resin is from the Heresy Armour set and the plasma cannon set.
However, the head is sourced from the Alpha Legion head hunters set (see this built miniature for reference). This was done to provide a unique variant for the sergeant, and also because the Alpha Legion like to mix things up a little bit. The hand on the left arm was sourced from Grey Knights and I've used it here to be suggestive of the sergeant pointing out the next target for execution by plasma fire. I like the overall aesthetic -- hope you do too!