what kind of axe was he using to slay that big monster?
I think it was a mithril axe. Only really will find out after Dawnguard comes out.
I want Umbra and two different kinds of generic sets.
I think umbra was lost or destroyed and that's why it wasn't in Skyrim.
Hopes for armor and weapon sets:
Adamantuim - for the heavy
Mithril - for light
The axe in the trailer looks like an Adamantuim weapon to me.
I thought it was a mithril one. I'm basing my theory on the fact that according to lore, mithril is the only weapon that can kill gargoyles.