You get vanity armors and weapons.
The armor sets are complete sets, it’s one item that you equip but shows a complete outfit. They don’t look really great in my opinion, they are recolors of existing armor sets and the color scheme is really… not great in my opinion. The texture got very few details, it looks like a plastic armor.
You get armor sets on level 20, 40, 60 and 80, they all look different, I don’t have screenshots of all of them, only from the level 80 armor.
On level 80 you also get a box that, when opened, drops all the vanity weapons for your class. A ToS for example will get a Staff, dagger, blunt, sword, polearm and shield. An assassin will only get daggers. The weapons got a rather weird coloscheme as well, they are black and dark red, kinda looks like they are made out of some “lava infused obsidian stone” attached to some metal parts.
The only thing I kinda like is the 2 handed axe you get for Barb, HoX or Conq, it looks very similar to the axe the T3 boss Hollow Knight is using.
Additionally to getting the items on the unconquered character they will also get added to your claims which means you can claim these armor sets and the weapon box on every character on your account once (not sure about characters created afterwards but all your old characters will have the items in you claims).
EDIT: I actually can’t post any real screenshots because I don’t have my unconquered character unlocked and for some reason I can’t take screenshots in the character screen.
At the bottom of this page (https://www.ageofconan.com/news/unconquered_mode) there is a screenshot of the level 40 armor, the level 60 and 80 armor are robes (basically have a completely different look but with the same color scheme).