For speed I kill the three sets of snakes before the snake boss, the snake boss, the three sets of snakes between the snake boss and Collusus, the 2 wandering trolls in that area, then all the elementals around the Collusus.

After you drop the Collusus, leave his room and jump into the water. Swim over to Moorabi's area, kill one roamer, pull the trolls and kill Moorabi. Then move to Eck's area and then on to the final boss.

Is there a faster way? (My way, thanks to tips from this forum, skips the trolls on the walk down from the Collusus to Moorabi.