Maximum strength, decent duration and high durability build for Lethal Progeny. Activate Empower first, proc [Growing Power] and [Energy Conversion] for summoning high level Sentient allies, and then stand in a zone created by a Kitgun equipped with a Residual arcane to activate and stack Theorem Infection to buff allies/summons within 90m.

(If you can't or just don't want to invest 2 Umbral Formas into [Caliban], you can always use [Amar's Hatred] instead of [Umbral Fiber] for similar but diminished stats.)