[Equilibrium] buffs mean we don't need to run [Combat Discipline] to maintain energy, and can use [Corrosive Projection] instead.

Play pattern is keep 3 and 1 active, activate 4, prime target with 2, then click or press melee on target to use your 4 to kill it with slash and everything around it. You will (/might, depending on level) need to stack your 4 damage at first, and may need to cast 4 a couple of times on the initial target. Once they start to fall, [Ulfrun's Endurance] will quickly [Recuperate] your lost cast stacks, and you will stay at maximum cast and damage stacks.

You may opt for [Umbral Vitality] over [Fast Deflection] (but will cost more Forma). You will occasionally take some damage, as casting 4 with briefly make you visible, and your 1 does end and need to be recast. (Plus, who do you think you are, Octavia?) Whether you value the faster shield recharge or the extra strength is up to you.

Voruna is dangerously self-sufficient: her invisibility keeps her safe, her death-by-slash-and-status remains relevant through all factions and scales incredibly well, her AoE is immense and time-to-kill minimal, and she never lacks for energy due to [Equilibrium] and the health orbs that drop. Her greatest difficulty is with nullifiers, as she will have to deactivate her 4 to handle them.