The two members of the squad hail from two well known, and celebrated Space Marine Chapters: The Crimson Fists and the Black Templars!
(click any pic to enlarge)
I have painted some Crimson Fists prior to this post for a diorama as they are relatively simple to paint after a basic priming of blue; hardened loyalists to the Imperium, they are a decimated chapter splintered from the Second Founding's Imperial Fist Chapter...
(Vote on him at Cool Mini or Not!)
The Black Templars are also a splinter chapter of the Imperial Fists from the Second Founding, and while they follow the Codex Astartes (loosely); they are a an example of one of the Imperium's Crusading Chapters, organized into Crusades rather than Companies... just don't get caught on the wrong end of a Templar Champion!
(Copied from: http://warhammer40k.wikia.com/wiki/Black_Templars)
(Vote for him at Cool Mini or Not!)
Want to get a serious idea of what these chainswords can do?
Check out this video!
it is from the video game Space Marine... and it is pretty violent!