The fatebinders in the court note that Mark can swap his loyalties any time he wants and he can move around the whole world however he wants.
Yes - his loyalities with Tunon. He don't, well... really, Mark can like old guy. Or they can have a history.
You believe fatebinders in the Court can say for sure that Mark can or can't swap his loyalities with
Kyros?
Also Archons have no "locks" to prevent going rogue look at Ashe and Nerat for crying out loud plus Ashe lead a giant rebellion before kyros made him his/her Archon of war.
Kyros used to create such locks at least once. It's Sirin. Sure, Ashe didn't have such lock
until he lead a rebellion, "awakened" as an Archon and was beaten and submitted to Kyros will.
And no, Ashe and Voices don't actually rebel
in a game against Kyros. Voices even don't try to protect himself when Bladen Mark carring him into Court; don't know about Ashe. They can fight each other, of course - even if they are locked, they are locked for Kyros, not for each other!
I mean the man has no faction symbol and has kyros Brand on his arm.
Yes, that brand looks like something can be seal for me. Especially including that such brand placed on his "working instrument".
Did not stop Kyros from dropping one on Cairn after he/she did not want them around any more.
Because he knows Cairn, what can he do and what he can't do. And PC literally eating Edicts, so throwing Edict on him is just granting him more power!
When you ask Tunon how kyros recruits Archons he tells you this Tunon: "The overlord takes great pains to recognize potential. Before an Archon comes into their power, they will have faced the harshest scrutiny by an agent of recruitment if not Bladen mark himself.
Sure, they will have faced the harshest scrutiny, so?.. No arguing here.
I believe you forgot one thing. Every Archon is unique. So or Kyros have some mystical method to know what will happens with any Archon, or such scrutiny should show exactly what a talent new Archon shows. And, well, it really can be "a surprise of lifetime", as Mark names you when you kill him.
Also why legally make you an Archon as well?
Because there is an actual working Edict giving Kyros some (unexplained) power against Archons he proclaims (the very first - officially - Edict Kyros used; I'd need to go for a place in game when you and Lawdry speaking about it, it something in the very start of Act 3, IIRR). And that's a reason Archon of Water named
herself an Archon - she wanted to show she don't need Kyros' allowance to be one (and so she isn't a subject for him).
Because you're not really growing
Archon. You're growing
exarch. Formally, Archon isn't metaphysical status but... let's say "social" position.