I don't get any :(

I farm the shadow nexus with heroes just to get that final piece of armor to complete my hero wardrobe, but nothing ever drops. Can someone tell me how much % chanse i actually have to get some, and does using heroes reduce your chanses compared to being in a player team?

I had problems with this, too. I was able to solo (no heros/hench/people) 17 or 18 of the Portal Mages (not in a row, total between a few runs) and didn't get a single armor. Yet when 2 of my guildies did it, they each got 1 within 2 runs.

those armor pieces have the same drop rate as everything... but the more non-human players you have with you the bigger chance is you don't get those...

check wiki... they have a good explanation there...