I like the challenge dungeons just as they are for a first play-through. However, by the time I’ve reached Ultimate and especially on a 2nd or 3rd character, simply traveling to the key door is almost a play session all by itself. None are particularly near a portal and all have a “foyer” level you must beat before even getting to the door.
I’d like to suggest that after some interval the gated doors become more accessible so a quick session could include one of the dungeons. I’m thinking something like beating the game on Ultimate, or reaching 100, or once you fully complete each dungeon, it then becomes accessible to a main camp somewhere with a portal. That is all. I love the initial design and the key mechanic, but once you reach cap and all reps are maxed, and you have millions in currency with nothing to buy… it’s very bland to slaughter through a couple hundred mobs just to get to the door so your play session can begin.
Thanks for your time.