There are a few things I have found.
I don't now exactly when or how, but at some point I started being being able to Clasp head equipment and necklaces, as well as rings, gems and mindstars. I think Hellcommander spoiled this one a bit in the main thread, so I assume it is something that has chance to be unlocked when using Clasp? But, yeah, without an unlock message, it's kind of hard to say when it happened
I found that Consuming the Blood of Life and then using Gluttony will cause it to grant you a passive effect which resurrects you on the spot when you die (i.e. no death message or anything, just restored to full life). That's pretty cool, especially considering the discouraging messages you get when Consuming it.
Consuming the Tooth of the Mouth reports that it will improve biting attacks, but I'm not sure exactly what this does.
I've had a few items with the 'inspect' option that just give a message saying it seems interesting, but you are unsure why. I believe Blood of Life was like this, but other Uniques that gave this message didn't seem to do anything when Consumed or Upchucked. So it's a little confusing what will and what won't do something.
Eating the Heart of the Sandworm Queen is how an Avatar unlocks Burrowing Beast, in case anyone hasn't found that one yet. I suspect corrupting the heart before you eat it would have an interesting result as well, but I haven't had the chance to try it.
One thing that I was hoping
would trigger some kind of unlock was siding with the Assassin Lord in the Hidden Tunnels as a Ritch. Considering the theme of the Ritch, the fact that siding with the assassin is utterly pointless after you unlock Poisons, and the fact that Ritch is the Avatar who would get the most benefit from saving the merchant, I figured this would be a good spot for a little hidden surprise, but, sadly, there was nothing.
Here's something interesting: Has anyone inspected The Summoner? If you do you will learn a couple things about them. One, they are apparently a Thalore, and, more interestingly, they know the blighted summoning
prodigy. Hmmm... just what kind of Zigur-hated, blight-wielding, Wilder outcast are we dealing with here? Maybe if I ever make it beyond the tier 2 dungeons, I'll find out
After completing the quest Jogging Memories part 2, you start Jogging Memories part 3, which sends you to a number of the randomly located dungeons in Maj'Eyal. I'm curious how others approach this quest. There is also the ominous, red-lettered warning to not
go to Dreadfall at this point, which of course just makes me want to go there even more. I've only made it to this point on one run, and I decided to check out the Ruined Dungeon instead. Sadly, my run ended to one of the guardians.
Also, regarding this point in the story progression, I'm not absolutely sure what all of the dungeons are. I, of course, don't have the quest up at the moment, but I remember that the only one I was 100% certain about was the Ruined Dungeon.
Think that's all I've got. I'm happy to share what I've found with those who don't mind having things spoiled, but I probably won't check up on this thread for a while, as I don't particularly like spoilers myself