I noticed that my hydra damage is not scaling. My dps is around 221k. It is critting for maybe 70k (at the most). I equipped a crappy source and 1 hander a little while ago and the hydra damage was about the same (100k around dps) which would be 60% paper dps.
So that would be like 31% paper dps with a skorn :(
Which would mean hydra is not accounting for increased attack speed or critical hit damage
(possibly the IAS, but not the critical hit damage).
The signature spells are doing something around those lines as well.
Storm armor is 100% weapon damage and crits for maybe 340k which would be around 100% weapon damage.
Forked lightning crits for maybe 140k....
spectral blade like 180k
magic missile seeker around 400k (which might be about right)
living lightning 18k (lol)
I have 511% crit damage
If I remove my active skill and walk up and slap a mob with my weapon, I will white hit for around 45-60k
which means anything that did 100% weapon damage crit for 200-300k
and disabling critical hit damage living lighting actually hits for 2k (3.3333% white damage).
Arcane hydra hits for around 40k max (white damage)
which is more or less 60% of my white hits.... so no IAS or crit damage factored in there at all.