How should I continue?

[Illius3000]

Well I finished the Lith mission ( Just the first 5 waves. ) and I am curious about how to continue. The reason is because I still need to complete two things to unlock the Venus Junction ... namely these two ...

 

Should I go for the following order of quests ... Cambria -> Gaia -> Pacific -> Mantle -> Cetus. Or should I go for a combination of those missions in order to get those last two requirements to unlock the Venus Junction? Personally I would prefer it that I could do all five missions, but I do not know if this is possible.

[(XBOX)MerlyBR]

Complete all the missions first because you can find eximus in then anyway and second you can use then the level up and put the mods

[(PSN)jFresh215]

Just know that all nodes give you a small amount of mastery points. I would just go and do all nodes before moving on.

[Proslackernifty]

You can apply mods to your weapon or warframe in the arsenal.  If you don't have enough mods to fulfill the requirement, keep doing missions until mobs drop more mods for you.  Also, you won't be penalized for doing missions in the wrong order.  You can do them in any order, change your mode to public if you need help.  Other people are sure to be running these missions, so you don't have to go alone. 

Finally the eximus units can be found in any mission, but they are especially popular in defense and survival missions.  If you go to wave 10 on defense, I think you are going to find a few eximus units for sure.

[Illius3000]

Thank you every one, I will do all 5 missions first for the Mastery points and Rank ups. And if I do not get to 3 Eximus during those missions then I will replay the Defence mission to see if they appear in there.