I love the Storied Realms bosses, they were all engaging and had unique mechanics. I'd love to see them appear in higher tiers in some way, Vault seems like the easiest answer.
This would also allow some of their materials to be available at higher tiers, and open more mid-to-high-end options for Crafting for the current stage of the game.
The bosses appear in Boss Rush, but they show up randomly, which makes it difficult to obtain specific loot without spending time with bosses that aren't as useful. I'd still like to see this enhancement fulfilled, so that the story mode bosses can be engaged at T4/T5 to facilitate gathering appropriate level materials.
Technically, JAna can reincarnate as pretty much any monster found in the realms. If Jana could reincarnate into Fabled Monsters buffed up to T4/T5 Vault levels would also be cool.
A couple of members of the community have discussed in passing the idea of having randomized bosses at the end of vaults, and here we find the idea once again. Personally, I would love to see this implemented!
The idea of fighting (for example) beefed up variants of the Bound Sentinels all at once, as a group, is very appealing to me. It would be a very different dynamic compared to the boss fights that we currently have, as you cannot just all focus one target in quite the same manner.
Plus, while materials you get from storied bosses are somewhat useful at the stage you get them, by end-game they are vastly outclassed. As mentioned above, if their boss fights were introduced to the vaults as well, it would provide justification for the creation of Tier 4 variants of those materials, some of which had very interesting stat combos that could mix-up late game quite a bit.
This could also provide a more concrete way of obtaining rarer fabled materials such as Fabled Carnute Hide from Yex, and Fabled Harpy Hide from Magwytch!
Please seriously consider this feature! <3
To add to this since I was going to make my own topic on it as well:
Honestly, it'd be cool to have the RNG aspect of the vaults also apply to which boss is at the end, I don't know if many people would share that sentiment, as it takes away from redoing the story bosses in their own realm, but that could be the pre-watch repeatable items.
Beefed up story bosses or something later down the development road would be really nice.
So you load into the desert, and you get the Giant, or Sheliak, or Yex (radiant)
Load into forest you get Elder Eoten, Jabber, Azazel
In Swamp you get Humbaba, Queen, Bound Mob (Somber)
The only issue would be the materials, but that could allow for tier 4 or 5 versions of those materials since I think they stop at tier 2-3 in the story realms.
I listed them based on which biomes they're in, in the story realms, however, the bound legion being in swamps might be very rough for players, so that might need to be swapped to a different biome, because the disease puddles alone make the Swamp Vault difficult for players.
This would probably break the lore since Storied Realm bosses are specific to the story.
Maybe the Difficulty slider can be unlocked to be unlimited instead of having a difficulty cap. Then you can just sleep to respawn the boss in the story and go fight them again at a higher difficulty.