Killian responds to Saxon:
"Good man.
Aye, yer animal is a right well fighter - a good addition to tha team - we'll be makin' suure nothin' comes up a-behind 'im."
Killian helps Kreeg out of the pit, and when Kreeg reminds Killian he speaks Goblin, Killian says quietly to both:
"Good - now make sure they feel like they'll be safe if they surrender.
Once I'm up on the other side, I'm gonna finish off tha bastards, fer slaughtering our lads!"
Killian's back is to the goblins, so they can't see the rage reflected in his face (them being blind helps, too).
Once the guys are ready, Killian will quickly but carefully jump/fall into the pit (having someone hold the other end of his rope to avoid taking damage, if it's a dangerous descent).
Then he'll maneuver his way to the other side of the pit, and throw the rope up to Mzarem, hopefully waiting up top to grab and pull him up.