This afternoon I was searching the interwebs for some fluff about the Mantis Warriors, right now there really is not too much to be found. After Imperial Armor 10 I figure that will change. This is not a bad thing, the lack of fluff is one of the main reasons I was drawn to the Chapter in the first place. However I am looking forward to reading about them in Imperial Armor 10 to find out more about them.
In the mean time what I have found is that the chapter is known for having its own distinct close combat tactics. This is something that the veterans are trained in as they progress up the ranks. Another interesting thing that I also learned was about a combat haze that in the heat of battle the battle brother will only see the enemy, much like tunnel vision.
With those interesting facts, it made me think and not only the codex Space Marines would be a fitting choice, but that Blood Angels could be fitting as well. The tunnel vision (Black Rage) would fit in with the fluff that I have found so far. Also the close combat tactics would also work with the assault nature of the Blood Angels as well. So those are really the only two points I have for using the Blood Angels Codex.
Now another codex that I was looking at is the obvious choice, codex Space Marines this gives the chapter plenty of options. Most of those options are available in the Blood Angels but there is no Black Rage with the Space Marines.
Think coming up with a list might be a good start, so I might want to do that, but in the mean time I need to pick a codex and run with it.
Hoping to get some feedback and ideas, so questions and comments are welcome.