Guardian Rank??

[Tsuki!]

Best farm? Ive heard Scraptrap with a Moxxis Endowment is the best way to farm

[Richargood]

Kill Ruiner on TVHM, Mayhem off, with BScience xp boost and Moxxis Endowment. Ruiner is one of the bosses that gives most xp in the game and he also is the closest to your spawn. You can kill him before even touch the ground with any Vault Hunter as long you are in mayhem 0 with mayhem 10 weapons. You can try with Graveward too, same amount of xp. Scraptrap doesn't give as much xp, but at least you don't have to save and quit. Just remember to activate the xp boost and to play in TVHM on mayhem 0.