I have lots of marines still in boxes. Tacticals, Devastators, Veterans, Terminators and of course the Dreadnought and Heroes... I think that Tactical squad is good to start with. Here´s five of them finished in Serpents of Hellfire colors. (5th company 2nd tactical) Some details still missing, like the chapter insignia (same as Dark Angels), but I´ll add them later :)
The Serpents are Dark Angel successor chapter, one of the Unforgiven, and pretty much all about "Something went wrong in the implantation of the gene-seed". As we know, all Neophytes don´t survive it, or it drives them mad... The Serpents are mentally unstable punch of warriors. Too unpredictable to be a Dark Angel, but too valuable to throw away... in the eyes of the inner sircle. So they are kept as a secret chapter, deep inside the Rock. They are used in desperate or secret missions, to spare valuable Dark Angel lives and to maintain Dark Angel diplomatic impartiality in some shady campaigns.
Not the most prosperous chapter... They like to collect combat gear as trophys, from the fallen enemy. (nice excuse to make some interesting convertions...)
Serpents leader, Supreme Master Catulus Übermann takes orders only from Azrael of Dark Angels.
I apologize... I ment only to publish the picutre, but got carried away with the writing!