The first two don't cover Istvaan only the run up and the third and fourth are more about the culling than the Dropsite Massacre.
waaagghbiker, are you telling me that Imperium Secundus wasn't important? are you telling me what happened with Vulkan wasn't important (won't say exactly as that'd be a spoiler :u )? also to you again above, the first two do provide the background information for why what happens at Istvaan happens. Also to answer the fellow asking for istvaan, as the guy above me says, the 3rd/4th have the culling/virus bombing at Istvaan III. Fulgrim does also again feature Istvaan III. the dropsite massacre is featured in a number of books, being Deliverance Lost, Scripts volume one (one of the short stories if I recall correctly), Scorched Earth, Vulkan Lives. and First Heretic I think? maybe want to browse for a plot summary of the short stories feature in books such as Tales of Heresy, Age of Darkness, etc. I can't exactly remember what are in those. And much to my regret, I don't own a copy of the Imperial Truth or Collected Visions so I have no first hand knowledge of what's in either. Oh and Visions of Heresy is well, kind of a reference book for the Horus Heresy so there's that. @ veda raa bottom of previous page, I'd just read em all in order
Nykona Sharrowkyn- Raven Guard. He shot Fulgrim in the face with a sniper rifle! And then he killed (for the first time) Lucius one on one in a sword fight!
I'm fairly sure after Fulgrim gets shot he technically dies till Fabius comes over and does things to his face till he ressurects.
Not for me, I really like the the emperors children, fulgrim might have been a bit of a panzy, but at times really kicked some serious ass, 2 primarchs, ripped up a avatar and countless wraithlords, 1 of best yet underated warriors. Your mighty sharrowkyn left his primarch behind on istvaan,escaped fortunate enough to be amonst the shattered remains of a beaten legion. sure i also understand why people dislike lucius perhaps nobility is not his strong point,he was a dirty traitor and saved himself, totaly screwing over his own company of men, but lucius is still sword swinging in the 41st, sharrowkyn long dead dying a beaten champion of a beaten legion..
Sharrowkyn beat Lucius twice! First time he scarred his once perfect face and the second time he scarred and killed him. Sharrowkyn might be dead but Lucius died first... and then once more after that. I don't remember reading about him leaving Corax and the rest of his bros behind on Istvaan though. Raven Guard took a massive beating at Isstvan but I wouldn't say that in the 41st they are a dying legion.
During the dropsite massacre as evidenced so splendidly by Vulkan Lives; Legionaires just scattered in a full retreat to whatever landing vehicle was nearby as such the aptly named "Broken Legions" dispersed and scattered across the Galaxy in warbands made of members of all three legions. So Sharrowkyn didn't leave Corax behind he was just seperated from him and his legion in the kerfuffle.