This Riven challenge is super easy if you have Equinox: Just build for max Range + Strength then some Duration and Efficiency. The Equinox Prime build below is a zero Forma build and works fine for this challenge. It focus on Range + Strength but also some Duration and Efficiency. Battering Maneuver give us a little longer Aim Glide duration - with some Forma we could use Patagium instead, which would give us much longer Aim Glide duration. But it is actually not necessary for this challenge.

Make sure to equip the veiled Riven mod and start the Tessera Defence mission on Venus in solo mode. Use an Energy Restore to fill up your energy bar before starting (i.e. before you go to the defence target). Make sure you are in Day form (default), then cast the #4 Mend & Main ability and just run around the looting energy orbs as the enemies die. As soon as the last enemy is killed a drop ship will show up - quickly bullet-jump and aim-glide.

This mission has at least three different tile sets but on each one I have tried, the drop ship always show up immediately after first wave so be ready! On some tile sets another drop ship show up during 5th wave.

You will likely not get all the required kills in one mission, so just finish the mission and extract after wave 5 (or abort if you prefer) - then repeat the mission again one or twice more until the Riven is unveiled.