The Commander Lilith & the Fight for Sanctuary Add-on for Borderlands 2 has 6 achievements worth 250 gamerscore.
Complete the mission "Paradise Found".
Defeat the Dark Web.
Allow Tiny Tina to arm the moonshot cannon.
Activate the Backburner's firewall.
Defeat Haderax the Invincible.
Equip effervescent-quality gear in all slots (except class mod).