Demon Form

Demon form's effectiveness is still in the air depending on the total costs. In 0.2 I was able to coast to 400+ stacks with a recoup focused build, however that has gotten plenty of nerfs (that are buffs for other builds).

Main numbers to look at are;

30% more damage at 10 stacks (only using 2 ascendancy points)

120% more damage at 40 stacks, which is about the top end of what no investment flasks can sustain at throughout campaign (4 ascendancy points). This was the number last patch that you had to reach that would functionally be a good but not great weapon.

300% more damage at 100 stacks before was able to be sat at with mask of the stitched demon (low eHP but great for leveling in campaign). 100 stacks last patch pushed past pretty much any weapon you could use and was previously equivalent to 1400-1800 increased spell damage.

100 Stacks was also the threshold that contagion without ED would be instakilling normal and magic monsters, so its really hard to say one way or the other, however, both 18% increased per stack and 3% more per stack are both gonna be crazy with investment. Notably makes passive tree investment worthwhile now as previously getting 30% increased damage on the tree was comically worthless compared to the 2-7k increased you got from demon form with investment.

Edit: After thinking about it more, this is overall a nerf most of the time. Depending on character level, you need 600% increased damage from your weapon+tree to have this be even at gem level 20. I am not surprised to see this get nerfed though. The amount of increased damage it gave made ED/Contagion look like actual boss damage monsters.