Dungeon (new kind of encounter)

- New kind of ecounter you can sometimes (rarely) find on a golobal map
- It utilizes current underground areas (crypt, slick, seepage and whatnot) to form a multileveled dungeon to explore
- All levels in the Dungeon has the same biome, but we can gradually change the lighting for each level to make it more ominous as you go deeper
- To enter the Dungeon you need a waystone, and the first level of the Dungeon will have mods and area lvl set by that waystone
- Every subsequent level will have +1 area lvl from the previous one and +1 random map mod to the initial set of mods, to boost difficulty and drops
- Dungeon can't use tablets (similar to unique maps) or host major mechanics like breach, abyss and such (I feel like stacking mods and area lvl will make it messy enough)
- Every level of the Dungeon is a separate instance that once entered can only be completed or failed (i.e. you can't restart it and farm infinitely)
- You can use multiple portals if your initial waystone provides more than one AND you'll get new set for each level (so unless you're extra greedy this is the time to apply some safety measures)
- On each level there's a boss (any mobile boss that doesn't require special arena will do, i.e. dungeon boss doesn't have to be tied to particular map the dungeon is based on)
- Once defeated (HP at 5%) boss drops some stuff according to its difficulty but doesn't die, instead it escapes while opening the entrance to the next level
- With each level boss gets more HP and one extra monster mod at random (if you ever fought a mob affected with too many essences or wisps you'll know what to expect at deeper levels)
- The number of levels in the Dungeon is limited, but random (I'd say from easy 3 to ridiculous 10)
- You can leave the Dungeon after the completion of any level and get back at any time to continue from the next level (it will remember your progress)
- At the end of the Dungeon and after you kill the final stage boss there's Treasure Trove of Untold Riches (loot in the trove is proportional to the number of levels and scales hard for especially deep Dungeon)

Basically I want an encounter that scales as you go. Somewhat similar to Delve (and I sure hope to see delve in PoE2 one day) but not exactly. Dungeon would be more compact and have very particualr goal: hunt down the boss and get his treasure. Kinda old-school and simple like that.
First couple levels will feel more like regular maps, but the deeper you go the harder it gets and the quantity/rarity of drops should reflect that. Ultimately Dungeon should be pretty rewarding even if you can't clear it fully and reach the treasury right away. But if you can clear it, then it should be nuts most of the times.
Basically players shouldn't feel like they just wasted a bunch of time and went through a meatgrinder for a pile of garbage. Otherwise people will ignore dungeons altogether, cause let's be honest, nobody likes to crawl through underground maze-like maps in PoE: they are awkward to clear and bad for business. But I bet you can make the Dungeon desirable with high enough potential for a good loot.