Re: Berzerk on a Helm
Staff mods are limited to spawn on an item only if the item corresponds with that skill (1.10 patch and later). What this means is that since a skills like poison dagger requires a dagger to use, it will not spawn on wands, or shields. Since daggers don't have staff mods, this skill doesn't spawn normally. This includes all the barb combat skills except leap on a helm, holy shield on a scepter, and poison dagger on wands or heads. There maybe more, but these are the only ones I can think of.
There is a feature in the game however, which is thought to prevent game crashes, which will allow these skills to spawn. If the game choices one of these 'illegal' skills, it will fail, and try to pick them again. If the game fails like this 6 times it will allow any staff mods to spawn on the 7th. The chances of this happening are very low, but possible. So every so often you'll see a holy shield scepter. And even though it doesn't seem that great, it will probably trade for more then you've ever seen.
As far as that helm you have there. Well simply put, it sucks. Although it is very rare, the eth really kills it IMHO. Since a merc can't make use of that helm the only thing I can see being done with it, is some sort of a twinked helm for a zerk barb that wants to focus early points elsewhere, like say BO. Maybe a titan zerker. Other then that, I would save something like that simply for collectors value.