To anyone who said I exploited, I didn't and never would.
Let me explain how it went down.
I finished my eternal embers part the week we got 6/7 HM (the reset of July 5th) so I started my branch quest the next week (the week of July 12). People didn't realize you could get the portal quest items from normal mode and not have to kill the bosses so in the end we got all the quest items from normal mode bosses and killed the legendary boss. After we killed the legendary boss we cleared 6/7 hardmodes on the week of July 12th (the same reset we did portal quest). Each 25M heroic boss drops 50?-64? cinders with normal rag at the time dropping~55ish?
I collected all my cinders and got the runestaff about halfway through the raid week of the 26th, leaving about 2-3? bosses up that week for me to collect souls from. Heroic 25M bosses give 17-19 souls per boss. So even if I got the worst luck in the world at 17 a boss I still would have made it in 2 1/2 weeks.
I collected souls from those 2-3 bosses + the next two full weeks to get it.