So if you are working on A World Awoken and have Storm Chaser as the last achievement (which most of us will). You will get 5 achievements and 165 achievement points for killing 1 trash mob.
Probably the most achievements and points you can get in entire game in 1 lump sum for killing 1 trash mob.
Sandstorms in the Waking Shores: 5pts
Chasing Storms in the Waking Shores: 10pts
Storm Chaser: 10 pts
Across the Isles: 40 pts
A World Awoken: 100 pts