Shade ult on monsters - 600hp, no bonuses:
427.5 - Daggers, Sword & Dagger (H2)
379.5 - Spear (H2)
300.5 - Dual Swords
212.5 - Two-Hander - 
balanced - 
Overpowered
177.5 - Glaive (H1)
161.5 - Sword (H1)
H2 = 2nd heavy attack
1016 ult dmg can be reached with the following monster universal build:
Daggers or Sword & Dagger
40% crit power
10% monster
15% grim talent
20% shrapnel
25% barrage
It’s possible to add off-balance or WHC tag bonus to this.
This was fun to do back when the daggers dealt about 250 dmg without bonuses and that was already borderline op back then.
With only 250 dmg per ult you are already able to kill a monster alone on legend but you will need a purple pot and the extension trait but you will only have about 1 ult margin of error.
The above is in my opinion what should be aimed for with the highest difficulty. So I will most likely be disappointed once winds of magic comes out.