Menace in the Zarek Valley - Buca buca!!!

The adventurers, along with their newfound orc buddies, travel back to the tribe's encampment. They learn a lot from the old shaman, called Gork, who prepares them for the confrontation with the new chieftain.
Once there, they stride (mostly) fearlessly into the encampment, and they are greeted by the chieftain and his posse. This includes a banner bearer, a drummer, an orc carrying the corpse of one of the sick dwarves on a stick, berzerkers, shaman, and a couple of guys in red plate armor, carrying two-handed axes. The chieftain himself rides a huge boar.

I don't remember the specifics, but long story short, Solid challenges the chieftain, who charges in.

Close to defeat, the chieftain calls on his allies. This causes a rupture within the orc tribe: some side with their chief, while others decry this blatant breach of orcish honor and etiquette. A large fight erupts.

Orcs die on both sides, including the old shaman, Gork, who is killed by a demon soldier.

The adventurers themselves get pretty worn down.

Finally, they do manage to defeat the demons, at which point the orcs stop fighting.

With the shaman dead, the adventurers no longer have allies among the orcs. However, the orcs are pretty happy to have been relieved of he demonic influence. One strong looking berzerker called Narg declares himself the new chief, and allows the adventurers to leave. He promises to take his tribe and move from the Zarek Valley, never to bother the humans here again.

During these final negotiations, Groin asked for the corpse of the dwarf, to be able to lay him to rest. The orcs refuse, stating that the corpse is their trophy. Groin's player responds something like, "Na buca." This translates into something like: "Well, crap." But I liked the word (which roughly means "butt"), pretended that the orcs do not understand it, and they took it up as their new battle cry. This gave the title of the session.