
The Fortuna bounties are also probably your best choice (unless you need the standing for Cetus), because the bonus objectives are way easier to do here.
Fortuna Bounties: Again, check the rotation. Plains of Eidolon Bounties: Make sure to check for the rotation of the bounty to get the relic you really want (there is an A and B rotation for the Lith and Axi relic). Orokin Vault: Either use endless missions or try the two Capture missions and get a lot of unvaulted relics within a few minutes. Here is where you can find the new relics: As with all unvaulted items you’re not going to find those new relics in the wild, but you really need to farm the right missions. With the unvaulting of Saryn Prime and Valkyr Prime Digital Extremes introduced six new relics to the drop tables (Lith C5, Lith V6, Meso N8, Neo S13, Axi S5 and Axi V9), which will give you all the primed parts for the added weapons and Warframes. You’re also able to get your hands on some special skins and other cosmetics for a limited time, so head into your market and buy what you like and want. Of course both Warframes are unvaulted with their own signature weapons, so you’re also able to farm for Cernos Prime, Nikana Prime, Spira Prime and Venka Prime. Both Rhino Prime and Nyx Prime (which have been unvaulted in the last few weeks) are back in the prime vault now.
There is currently no statement from Digital Extremes about the end of the current unvaulting, so get your primed weapons and Warframes in the next few weeks before they vanish again. For the first time in Warframe history, Saryn Prime and Valkyr Prime are leaving the Prime Vault and will be farmable for a short amount of time – how long, we don’t know.