Obtaining Soul Crystals above lvl 10

I'm a mage looking to get an SA on my Sword of Miracles. This requires a lvl 12 SA crystal. I know that earlier, the only way to obtain one was to slay a boss such as Antharas, Baium, Lilith, or Anakim. After C5 launched, I'm now hearing a lot of rumors about other mobs that will allow you to obtain lvl 11 and 12 crystals, such as killing the lvl 70 rift boss, or certain less powerful raid bosses. Is there anyone who has more information on whether any of this is true, and if so more information on it such as "Raid boss X will get your crystal to lvl 11" or "Raid boss Y works on lvl 11 crystals but not lvl 10". Any help would be appreciated.

Same now, exept they added a few more RB whith lover chance to lvl crystals.
Look in the patch notes.

Also some of them boys only lvl up 1 crystal. Kinda sux imo.

Also some of them boys only lvl up 1 crystal. Kinda sux imo.

dosn't flood the market

then again

it leads to camped bosses :-/

One of the RB that has a chance to upgrade 1 crystal is the vampire RB in the Cursed Village.

So far I've checked twice and nobody there each time. Is this RB particularly hard in C5?

Can anyone describe a group that successfully raided this RB in C5?