This Rest & [Rage] build is optimized around Rest for stealth killing and Affinity farming. You can either level your own weapons or help a friend level their Warframes quickly with this setup. Make sure you change your primary emission color so that your Warframe will have Rest equipped.
[Enemy Radar] paired with [Primed Animal Instinct] allows you to see enemy spawns well before they see you, making it a lot easier to stealth kill without being seen as you know where to cast.
[Preparation] is my Exilus Mod of choice due to its utility as it minimizes Energy Restore usage. Feel free to replace this mod with [Cunning Drift] if you want the marginal range bonus it confers.
I use Arcane [Fury] because I also use this setup to Forma Melee outside of ESO. Swap it with your preferred damage Arcane if you will be using a different weapon type.
Adaro: Spam Rest and kill everything to level up your weapons or farm Focus, or let your friend do the same to level up his Warframe quickly.