There should be three heroic dungeons for legendaries. we could vote for them.
1: Titled monster dungeon: the baroness, the undertaker, or the inheritor.
2: mechanical creature dungeon: stake, scaraborg, or m2-wyvern
3: Double-monster dungeon: ithiander, granuy or firael
I think these would be excellent options as part of this idea.
Please consider this proposal,