Hear me out.
I know this is the wrong forum, but the CoE3 forum has no modding section and is dead anyway. Moreover I am working with sprites from CoE4, so technically this is the right forum... in some metaphysical way. Onwards.

Is there some known problem with CoE3 modding, where you can't add special damage (or benefit) types to weapons, or is it just me?
I am playing around with creating a new recruitment list for Necromancer, since I always felt the usual soldiers aren't very atmospheric and other classes got their own roster, too, but I can't give my units weapons that, for example, cause Disease on hit.
Well, more exactly I can, but it doesn't work.

newweapon "Harvester's Scythe"
wtrgrank 1
wdmg 6
wdmgtype 1
wlook 2
wsound 1
wnext

newweapon "HarvesterScytheDrain"
wtrgrank 1
wdmgtype 7
wdmg 1
wspec 161
wnext

newweapon "HarvesterScytheDisease"
wtrgrank 1
wdmgtype 12
wdmg 1
wspec 512

Ingame my new unit has the weapon equipped and shows the correct information: Slash damage, then Drain damage, then Disease. Even in battle everything seems correct in log: Slash damage applied, Drain damage applied, [target] is affected [by disease]. But when I actually check the enemy, there is no disease. Same with every way I try it. Normal weapons (not the chain stuff above), with resistance checks or without, special damage or special benefit (on enemy and friends). According to the game log everything is applied, but nothing is applied.

Am I missing something? Can't find anything about this being a known thing.
Well, and my command "diseaseres" is not applied to my monster, too. So, something seems off, but other stuff like this new unit...

newweapon "Flagellation"
wtrgrank 0
wdmgtype 2
wdmg 1
wsound 9
wlook 34

newmonster "Death Seeker"
copystats "Flagellant"
clearspec
spr1 "deathseeker01.tga"
spr2 "deathseeker02.tga"
meleeweapon 0 "Flagellation"
firstshape 1

newmonster "Soulless"
copystats "Soulless"

... works exactly like I want them to: A blood tainted flagellant, that damages itself every turn it attacks and then turns into a zombie (Necromancer theme, you know). So I can't be completly useless as a CoE modder.
Any suggestions? And thanks to everyone who read all this.

I hope I could make my problem reasonably clear, it's a bit complicated in English.

Edit:
Okay, I solved it.
The difference is how/where the damage of a special damage weapon is defined.
When defined under 'newweapon' it shows the effect ingame, but doesn't actually apply it. When defined either with 'meleeweapon x' or 'wnextdmg x' everything works.
Good to know.