A build and guide for soloing Plague Star as the notoriously teleport-heavy L⁠oki Prime.
Mod config shared with Loki Prime - Steel Path | Guardian Angel | Invisible Distraction | The Better Decoy for ease of use.

How-to/general gameplay loop:

• Setup:
  • You need an Archwing. Your best options are E⁠lytron(for warhead-based drone throws), or A⁠mesha or I⁠ztal(for base flight speed).
  • You need a sniper rifle equipped with [Amalgam Serration] and [Eagle Eye], to respectively make your Archwing faster and make it easier to zoom in on the drone from range.
  • You need this Pyrana Prime build - lower-ranked mods are fine, as long as you have the general build. Multishot is better than pure damage. Additionally, this Furax Wraith build is recommended to further increase the DPS of P⁠yrana Prime.
  • For this build, you need at least a rank 3 Arcane Pistoleer, a minimum of 190% range and 200% duration, for Switch Teleport and Energized Munitions respectively(if you can't get Energized Munitions yet, duration can be largely ignored), and optionally S⁠avior Decoy and [Decaying and Bleeding Dragon Keys](to speed up the first stage).
    • Note: Having both Bleeding and Decaying used to be greedy, but S⁠afeguard S⁠witch now provides 3 seconds of invulnerability on swaps - 6s with this build. This makes it much safer to lower health for Savior D⁠ecoy use.

• First stage:
  • If you're using S⁠avior Decoy, place a Decoy(your 1)within the cave itself, past the door. In most caves, this should prevent enemies from getting to it.
  • R⁠ush to the Thrax Toxin. Get the toxin, the faster the better.
  • If using S⁠avior Decoy + a Decaying Dragon Key, then find and sit in front of a convenient enemy(preferably a turret, if available, as they don't reload) until it fails to kill you and teleports you out. This should be faster than manually moving out of the cave for most, but possibly not all, caves. Otherwise, rush out of the cave.
  • If hosting, open the Nightwave menu to force the dialogue to skip ahead and force the second stage to start.

• Second Stage:
  • R⁠ush to the Toxin Mixer. Put the toxin in it. Put four Infested Catalysts and four Eidolon Phylaxis into the toxin mixer.
  • Defend the Toxin Mixer. There's no way to speed this stage up, and it's not particularly dangerous even solo. Use your Necramech to give it some free affinity, maybe.
  • Take the toxin.
  • If hosting, open the Nightwave menu to force the dialogue to skip ahead and force the third stage to start.

• Third Stage:
  • R⁠ush to the Drone. Put the toxin in it.
  • Use Switch Teleport(your 3) to rapidly teleport the Drone closer to the Boil. Where possible, try to teleport the drone to easy-to-see, high locations that it can path from, to make the next teleport easier.
  • If using E⁠lytron, you can use Warhead to throw the drone into the air to make it easier to see from range.
  • S⁠afeguard Switch makes any given location you teleport the drone to perfectly safe, in case you're worried about losing the bonus 50 standing.
  • If you're doing this in a squad with two L⁠okis, it is twice as fast when executed correctly, as one Loki can be moving ahead while the other teleports it, and this gets increasingly fast with additional L⁠okis.
  • If hosting, open the Nightwave menu to force the dialogue to skip ahead and force the fourth stage to start.

• Fourth Stage:
  • Use P⁠yrana Prime to clear out the infested that spawn and charge up G⁠alvanized Diffusion, Secondary Deadhead, Arcane Velocity, and Arcane Pistoleer. Try not to hit the spawn pods unless a Hemocyte is currently active.
  • Optionally use Decoy and Invisibility(your 2) to ensure that infested don't incidentally harm you - the additional sprint speed from Amalgam S⁠erration makes you faster than any given infested unit, so this is technically unnecessary but may help to group infested.
  • Once a Hemocyte spawns, stop attacking briefly, then use Energized Munitions(your 4) and clear out infested to activate P⁠yrana Prime's special effect. Then shoot the Hemocyte with your infinite ammo pocket shotguns - it should die extremely quickly.
  • Repeat until the bounty is complete.