This is the cheap beginner-friendly version of my Wukong Index build. Please check the main guide for a detailed explanation on how to use it.

Main build and how-to: https://overframe.gg/build/438326/

Alternative auras

I went with Pistol Amp as it is the cheapest useful aura for the build. Alternative useful auras would be Corrosive Projection (-enemy armor), [Physique] (+health), [Pistol Scavenger] (extra ammo for QoL) or [Steel Charge] for the raw extra points.

Useful stats

[Wukong]'s Celestial Twin inherits your health and shield, multiplied by your Ability Strength. When you move around using Cloud Walker both you and your clone will get healed per the distance travelled. It will [Recover] your clone's health and shield, but only the health for yourself, making shield less valuable.
Drop [Redirection] if you're short on points (using an aura with the wrong polarity) or replace it for extra health or ability strength with mods like [Vigor], [Transient Fortitude], [Blind Rage] if you have them.

[Enemy Sense] makes you able to see enemies on your minimap as we have to look in the other direction for spawn manipulation purposes. Flawed [Enemy Sense] range's is slightly too short to be useful but you can go without if you understand where the enemies will appear and in what position your clone has to be in in order to have a line of fire on them. Once again check the main guide about that topic.

Focus School

Use Zenurik's Springwell for easy energy generation, if you have Molt [Vigor] Arcane use your Springwell before summoning your clone for extra tankyness. This is not required, but nice to have.

To unlock the Zenurik Focus School you need to install a Zenurik Lens on a lvl30 frame or weapon then get experience with said frame or weapon to convert it to focus points. You can get those lenses from Landscapes bounties (Earth Cetus, Venus Fortuna, Deimos Necralisk). Mouse over the bounties to see their potential rewards, what type of lens is awarded by the bounty changes when new bounties appear. Zenurik is very useful to have in general.

You can quickly check what lenses are currently available on https://hub.warframestat.us/ expand the rewards of Ostron Bounty Cycle, Entrati Bounty Cycle and Solaris United Bounty Cycle then do Ctrl+F and type 'zenurik'.

Obviously using this cheap version makes the clone a lot less healthy, so you will have to keep a close eye on it to heal it with Cloud Walker (ability 2), or re-summon it as needed. It will still work fine for 2 or 3 Index rounds if you have the proper damage. Check the main build on how to get that damage with a [Kuva Nukor].