I’ve determined a way to better challenge the players when they group together, one of the initial problems I had with the system was challenging groups of monsters without destroying them, there is a particularly infamous case where the mad scientist revealed his badass amalgam of all the players monster only for it to be dispatched in the first round. Now the most obvious way to challenge larger groups is to pit multiple enemies against them, or add a threat or two, but those are obvious and fairly intuitive. What happens though when you want the showdown with the big bad? There are no mooks, no tricks, it finally comes down to the group versus one titanic foe? You could add toughness to make the fight last longer, you have to be careful about it though or you risk the players being barely able to scratch the opponent, you could add gnarly, but pair that with tough and you risk a party wipe in a long drawn out fight unless the players monsters have some broad toughness to defend from it, and use it without tough and you are left with an enemy who does good damage but ultimately goes down fairly quick.
What I do for these fights now is I tweak the way damage is applied to certain enemies
Mook/normal enemy for one monster, normal damage
Elite/specialized enemies for taking on two monsters, multiply the dice pool of each hit location by 2, this gives you a hit point pool for each hit location, for every 2 the pool is lowered, subtract one from the enemies dice pool.
Captain/ enemy meant to take on 3 monsters, like the above but replace 2 with 3
Boss/ enemy meant to make on 4 monsters, I think you get the idea.
So, what do ya’ll think?