LOL. When exactly does the optional mission (I'm assuming it's a reward for an optional mission and not a story mission?) unlock? Like after what story mission/chapter? Right now I'm on Wildlife Preservation and keep getting fucking killed by that damned Super Badass Loader that I need to kill to continue the quest.
It will definitely come in handy later on. I accidentally sold one of my purple or higher rated guns (I think it was magenta-rarity) to a weapon machine and didn't even notice until it was too late and my weapon was gone and couldn't be bought back for some reason.
Once I get and equip that and get a purple or higher relic or artifact or wtf ever it is that goes next to your shield in the bottom-right hand corner of the grenade/class mod/shield/relic or artifact inventory slot. Gunning for that one achievement/trophy that
unlocks when you have all equipped items in your inventory which are purple or higher-rarity.