Slash Dash now has a guaranteed slash proc. Considering it keeps you invulnerable while casting it, well... Excalibur now does an insane amount of damage while being completely unkillable. It also now auto-targets, so you don't have to aim anymore either.
How to play:
Activate 4 at the beginning of your mission. Then use Slash Dash until the mission is over. Ensure you're picking up Energy Orbs for Arcane Energize. Arcane Avenger will proc on the occasional damage you do take.
Take Heat or Toxin as your element for Chromatic blade (So any Orange, Pink, red, color for Heat, or any Green for Toxin) and use this Exalted Blade Build: https://overframe.gg/build/233071/exalted-umbra-blade/exalted-umbra-butter-knife/