Since before Sumeru, I’ve had this headcanon that all the Harbingers bear a Cryo mark (largely inspired by the Electro marks seen on Ei and Scara); through it, she could either fully possess her Harbingers or simply see and hear whatever the Harbinger in question was doing.
Most of them loathe it, but—whether out of devotion or a need for Fatui resources—they accept the mark and the Archon's constant presence.
The funniest part is that the Tsaritsa enjoys entering battles through her Harbingers, using the experience as training for her own final battle.
Sandrone is absolutely furious because the Banker’s caravan got cornered in the middle of nowhere and she’s been sent to break the siege: He stirs up trouble and I’m the one who pays the price; my robots are busy building teleportation gear right now—I am not fighting for that guy…"
Agent: "My Lady, Lord Pantalone has just headed into battle… he actually took a spear with him!?"
Sandrone, knowing full well she has to go help because that is the fucking Archon and she answers to the woman: I hate my job.
Ajax, battered and cornered by monsters in a dark pit in Nod Krai: Hm, guess I'll use the Legacy."
The Tsaritsa, back at Zapolyarny Palace in the middle of a meeting with Pierro, knowing full well that if the boy uses the Legacy, his body is going to get wrecked: Ajax, let me in, would you?
The Legacy: I hate that woman.
Rumor has it among the Fatui that Capitano has silver eyes and ice as cold as the Archon's—they say it’s because he is her champion, and they claim that sometimes, the Archon’s soft laughter can be heard when Capitano fights.
Before the flames consumed the woman, Ei swore she saw a silver gaze of pure hatred fixed upon her.
Nahida knows she is being watched throughout the conversation; she had assumed it involved the Segments—likely a mental communication network between them—but now, as she watches the Doctor leave, she notices a red eye and a silver one gleaming behind his mask. She also observes the beginnings of an ice crystal forming where the Doctor had previously stood.
Lord Pulcinella often spoke to himself; usually, during his afternoon sessions of signing and organizing documents, the dwarf would hum affirmative or negative responses before approving or rejecting the proposals on his desk.
On rare occasions, Lord Arlecchino was seen fighting with a scythe wreathed in red and black flames, yet his hand glowed with a soft, cold blue light; this led everyone to assume that Lord Arlecchino possessed a Cryo Delusion.
Columbina severs the connection when she asserts her authority; at times, she misses Her Majesty's gentle voice—the soft, pleased hum that would resonate in the back of her mind whenever she sang.
The Wanderer sometimes reflects on the moments he came close to divinity—the early times when a Goddess looked upon him, deemed him worth the effort, and interceded on his behalf. Sometimes he misses her care; sometimes he misses the sense of security that came from knowing she was there.
Pierro rarely experienced this, given that he was always by her side, but on the rare occasions when the Goddess gazed at something through him, he remembers thinking of the comforting warmth that only her coldness could bring.