The Lost City - From the Gate to the Southern Trebuchet (Part 3)

Now head for the far right corner of this area, looting the packs that the various Deathless warriors dropped when you destroyed them.

To reach the trebuchet, shoot 3 climbing arrows into the wooden walls. Climb/jump across the arrows to the right.

Then jump over to the ice wall, latch on with your axes, and climb to the top.

A Deathless archer comes around from the far side of the trebuchet. Shoot him or the Greek fire vessel next to him.

There's also a swordsman waiting for you on the trebuchet platform. Climb up there...

...and get him with your shotgun or use the Dodge Kill maneuver if you've unlocked that skill.

Loot the packs and grab some cloth—and possibly a few gold coins—from the container on the back left side of the lower deck.