That dungeon was a bear; I feel lucky that we made it through because I know many that it took several tries of giving up and returning another day to finally get through. Of course, that was before you could Google that 2nd to last boss's mechanics to figure out what you have to do there, lol.
Acadian and I did Crypt of Hearts last night; and it was another dungeon that the mechanics of one boss had all of us guessing on how to tackle her. I've done that one before, but with a group that knew exactly how to handle that 2nd to last fight. And I couldn't remember how to save my life without them there to tell me, urk. But we made it through by trial and error without giving up; and that is what was so Awesome about it!
What is the deal with them making the 2nd to the last boss the hardest in some of these dungeons?
Khajiit thinks that it is a tradition in gaming to make the second to last boss harder than the last, lol. This one can think of a few instances where this was true (please note that the following list is based on Khajiit’s personal experience. Experiences may differ)
Mortal Kombat- Goro was way harder than Shang Tsung.
Legend of Zelda: Ocarina of Time- Khajiit had a harder time with Ganondorf in his wizard form than his last one.
Super Castlevania IV- Death (grim reaper) was harder than Dracula.
Just a few examples.
And for an example of the hardest boss being last; all ll I could think of was Bowser!!!

No, seriously = I've never noticed how hard these bosses really are before, because I always came with a group that knew the mechanics of every boss fight going in. That makes a huge difference. I didn't/can't remember them; so always relied on just being briefed before the big fights. Well, without the briefing, we were all kind of going in there blind.
But we did make it, so all is good, lol.