Peacemaker

For this you need a match that actually has all five minor factions present - but you can check this immediately after starting by opening the minor factions window.

You'll get the achievements for maxing faction rep for each of the minor factions as you do this:

• Aluxian Resurgence - Friend of the Aluxi
• Pirates - Talk Like A Pirate
• Viturak Cabal - We Are Here To Stay
• Pranas United - Our Survival Is Assured
• Jiskun Force - Ally of the Jiskun

This achievement is soft-missable as if the homeworld of any of the minor factions is destroyed then you will no longer be able to max reputation with them (whether you destroy them or another faction does).

And, once you've unlocked this, see There Can Be Only One for then destroying them all.