In the Solar War (of the Horus Heresy series) the mining ship that Mersadie Oliton was on was attacked by "Red Armoured" space marines. However, are they Word Bearers or Blood Angels?
Mersadie is carrying a deamon to the Phalanx and that said deamon massacres the boarders it seems unlikely that it's the 17th legion.
However, I would have expected her to comment if she was being attacked by loyalist marines.
Which legion attacked Mersadie's ship?