Where is Cordana?

I’ve been looking for her for two days, killed the other four but I can’t seem to find here anywhere. I’d appreciate some help.
Thanks!

I’ve completed the Demon’s Bile quest up to killing Cordana. If I can’t find and kill her I can’t complete the quest and advance my Alchemy profession. I’ve looked and looked, hearthed back to Dalaran and flown back. I’ve allowed the instance to reset and killed all the other bosses twice and it looks like I will have to do it again. Can someone please tell me what to do here?

You take the second elevator that goes down instead of up. which is available after killing the 2nd to last boss. Just go past the last kill. Killing it solo is hard. It’s called “fallen”. something elevator. Then go into dark, lite the light thing and kill spiders then go along left side around pillar to ground kill some vengeance demons then walk in dark area you will find entrance. closed door will open go in and it will be dark. before fight lite light. Killing it is Not easy. solo even if your highest lvl.

I got it done, finally! Died four or five times but eventually succeeded before I saw your post. Thanks, though!!