To be equipped with Decaying dragon key. One cast of Sonar will immediately restore 80 Shields through the use of Brief Respite and the Double Augur mods. Through the Decaying Dragon Key, your Maximum shield is reduced to 75. As such, the sonar cast recovers full shields into overshields, and so it immediately recovers the full (1.3 seconds) of shieldgating Invulnerability.

Especially potent with hitscan weapons. With the 14x Damage Muliplier, you shouldn't have many issues killing things successfully, even in steel path content, and with arcane energize, your energy economy should be fine.
If in danger, just press 3.

If you still have energy issues, use Zenurik dash.

The Xata's whisper is optional, but I've added it in Preparation for new War and the sentients to come. Already does quite well with basically deleting Acolytes.

Do not use with infested or toxin lich/sister.

Streamline is at 4, at 5 efficiency is slightly too high to regain full shields with one cast of sonar.
Use to bypass new lich/sister damage reduction formula.

Multiple casts of sonar can stack MULTIPLICATIVELY if the weak spots overlap, so if you can afford to cast it a few times for tougher enemies, go absolutely ham. Multipliers of x14 stacking multiplicitavely? MMmmmmmmm. With two overlapping instances, we're already looking at almost 200x the damage.

It uses Speed drift to reduce the cast time of your abilities even more - very handy when they are a requirement for shield gating for survivability.
However, this means it requires 2 Forma instead of 1.
Primed Sure Footed can also be used here if required. This requires a Polarity on the Exilus Slot.
If the ability to swap between is desired, the build requires 4 Forma, with a Vazarin (D) Exilus Polarity, and a Naramon (dash) Polarity on Fleeting Expertise.