Return to Sender- Keeping quiet of Hanlon's plan of sabotaging the NCR within the rank to ensure all the lower troop start rallying and overthrow the NCR upper echelon. Never mention at the ending, but that's the whole motive of Hanlon crime.
Silus Treatment: Help Silus to sneak out from his captivator.
G.I Blues & King's Gambit: Instead of working a treaty between the Kings and NCR, sabotaged the whole deal by siding with Pacer, incite a full blown war.
Bounty of Motor-Runner: Make a deal with the fiend's leader; Motor-Runner to hand over his helmet in order to deceive NCR and make them think that the fiend in disarray.
Birds of a feather: When the whole backstabbing ensues, switch out your apparel into Legion's and take out both NCR and Van Graff.
Lucky Old Sun: Activate the Achimedes defense system, all the NCR presence will be eradicate. Legion then will take over the plant, ensuring a fearsome presence for Novac's citizen.
Powder Ganger in Vault 19: Don't complete their quest.
We are Legion & Oh My Papa: After Papa Khan nominate you as his heir after Camp Forlorn Hope Massacre, kill him(silently) and tell Regis to side with Legion when the war ensues.
How Little We Know: Report Cachino activities to his boss, and help the Omertas to finish up the preparation for attacking the Strip.
Hard Luck Blues: Save the vault families and doomed the NCR farmer by letting the radiated water continued to flow into their farm.
Eye for an Eye: Tell Centurion Aurelius about the bug given by the NCR, and help him by giving them a false raiding plan.
Heartache by the Number: Help Cass avenge his caravan's loss, effectively cutting NCR major supply line.
For Auld Long Syne: Enlist remnant help for Legion on the upcoming second battle of Hoover Dam.
Climbin Evry Mountain: Told Oscar to attack NCR main camp.
The Apocalypse: Target the missile to NCR's Long 15 base.