Wrathful Advance to instantly teleport anywhere within 33.12 meters, since the main downside of Aegis Storm is its mobility. It's better than Molt, with which sometimes you can get stuck and be unable to change direction, and doesn't need duration, which [Hildryn] doesn't care much about. For level cap, use Quiver and replace Arcane Expertise with Crepuscular.

I'm not using Molt Augmented because it takes a while to ramp up and doesn't fit her playstyle of casting and remaining in Aegis Storm.

For archon shards, 5 tau strength. It scales much better than going for more shields, especially with Arcane Expertise. With that and Madurai, she also reaches the 328% benchmark to fully strip in one Pillage cast thanks to [Corrosive Projection] or [Shield Disruption]. For even more damage, you can use [Precision Intensify].