First of all, your basic allied detachment for Blood Angels.
Librarian with JP
x2 Ten man assault squad with meltas and/or flamers and Power Weapons
1 Sanguinary priest with PW and JP.
This is about 660 points, but brings a whole lot of hurt to the table! First of all, they are troops, but also, feel no pain and furious charge hurts, add to that Divination and the ability to give the entire squad reroll to hits, and possibly a 4+ invul save, and you are talking just nasty.
Further, in 6th Edition, with the ability to take armor saves vs Dangerous Terrain tests, and FNP, assault marines are now able to jump in and out of terrain without fear.
Even further, if you are able to line it up, the Hammer of Wrath is sweet! Blood Angels assault marines are truly ferocious.
For about 600 points, what other better options are there? (That are Battle Brothers)
Chime in!
Jawaballs