Alephee filled in the gaps for Eren, supplementing the initial information received from Rodrick's classified reports.
The homunculus conjectured that the Elder Seed Artifact allowed Shallot to cast reflections of her intent upon her opponents in the form of Soul Reflection and Intent Reflection. As such, her opponents were forced to follow her intent when she reflected her will onto them using the artifact's powers.
Her Soul Sense merely augmented the artifact's powers, granting her the ability to wield them even against a formidable Titan, earning her the illustrious title of a Titan Slayer.
