I don't beleive you're asking more more difficulty as you are asking for something more dynamic. Because if it's more difficult, the process would be the same, just with a greater number:
Form a party with
4other players, go to the black shroud, kill 2 wolves, finish .
That does not sound any more appealing to me than your unmodified quote.
Instead, why not gather 0-5 other individuals, go to the location, fend off an entire PACK of wolves, with an Alpha-wolf that co-ordinates them that you can disorientate the entire pack by killing the wolf or scattering them with a farmed item that triggers a flee instinct in them. Have a selectable difficulty (1-5 stars) and choose how you approach the fight?
The wolf fight, more or less, is a Leve instance, works with the same basic components. There's no reason why the fight can not have both more dynamic feel, AND a choice of difficulty.
And I believe the player base sells itself short by fighting with each other instead of demanding more for all.