Okay, so this just popped in my head and I need to know—Won't the fact that Taylor hasn't displayed the Akura bloodline (Crystal armor generation) ability let others figure out she's not actually an Akura? I mean, it kinda seemed like it was sth they didn't want the world to know, at first. Or is it not sth that's observed in all the Akura clan members?
It's already been explained, so I might as well explain how Magic Bloodlines (seem to) work in Cradle.
There's basically two different ways Bloodlines seem to appear in Cradle, Mutation and Authority.
A Mutation sourced Bloodline
seems to occur the same way natural evolution happens IRL. An otherwise normal person is born through the usual methods, and their physical and/or spiritual DNA has a slight error in it, causing their body/spirit/soul/madra to grow in an unusual way, and this alteration helps increase survival and reproduction rates and eventually spreads out into a stable population, though thanks to Punch Magic and Life Extension what defines a "stable population" can range from "everyone on the planet" to "literally one family unit, possibly even only two people at a time, the mainline parent and their child-heir".
Because of the "Consume Remnants For Power" pipeline, we receive exactly
one firm canon statement on a Madra Mutation existing, so while we can make assumptions and extrapolate on the idea that people living and shaping themselves to adapt within a certain area will develop genetic traits (physical or spiritual) over vasts amounts of time that help them adapt to their local conditions, no one
explicitly has that going on in Cradle, so we come back to the one explicitly canon statement of Madra Mutation that exists (that I remember).
The Sha Family's Royal Madra is reportedly a spiritual mutation. This complicates things because the Sha Family is a
Monarch family, but we'll get to that in a minute, so first let's get the direct quote.
Royal madra, the rainbow-colored signature of the Ninecloud Court, is in fact a spiritual mutation of pure madra that occurred long ago in the Sha bloodline."(Uncrowned, Chapter 9)
So while it
could be a result of an Authority Bloodline, it's not spelled out as that and the above comes from an Abidan Report I'm inclinded to treat it as what it calls itself, a spiritual mutation, which means it's a quirk of spiritual genetics which was successfully exploited by the Sha Family to maintain their existence and control over the Ninecloud Court.
Said Spiritual Mutation allows them to use their particular flavor of Pure Madra to control the Madra of others by the way, but we've already seen a first person view on how a Sha Underlord might fight so I won't go into details beyond that right now.
The other type of Bloodlines is the Authority Bloodline, or the Bloodline Legacy.
When someone reaches Monarch, a/the core aspect of their spiritual journey is highlighted, emphasized, refined, and turned into a genetic Bloodline ability.
I am uncertain if this ability is "retroactively" applied, and given to existing bloodline members of the Monarch's familial legacy, presumably within their Authority, or if it only applies to those newly borne to the new Monarch.
Additionally, it's not
quite known if someone who already had a Bloodline Legacy who becomes a Monarch creates a new Bloodline Legacy, either a variation or a whole new Legacy altogether, but to be honest the available information suggests that it both is not "retroactive" and that if you have an existing Legacy when you become a Monarch you don't seem to create a new one or a new variation of it.
The two Legacies that we're certain of existing as an inherited Bloodline Ability are the Arelius Bloodline, which is a very strong expansion of their Spiritual Perception, and the Akura Bloodline, which is their purple gemstone madra armor.
Addressing the original question of "Are there members of the Akura Clan who can't use the Purple Armor?", the answer is actually yes!
The Akura Clan basically has two degrees of genetic closeness, which
essentially boils down to the Main Family and the Branch Families.
It's actually really easy to figure out which are which by the way!
Is their first name some sort of Virtue or Vice, some sort of Single Word Personality Trait?
If so, congratulations, it's a Mainline Family Member!
See, Malice has this
thing about the whole Virtue Name Thing, especially because it was used with
her with the intent of her becoming the Malice of/against Dragons and Dragons killed all of her family members when she wasn't a Monarch, so if you're born in the Mainline then Malice pops on over, does a scan of the baby brain, and slaps down a one word Virtue Descriptor as their name based on what she determined about the newborn baby's brain structures plus probably Future Sight to a small degree, and then bounces to whatever else she has going on that day.
So, Taylor being a member of the Akura family isn't strictly
unusual, except for the name Taylor probably being
mildly unusual but honestly not significantly, and also the Akura sometimes adopt people into the family without them needing to marry into it, so that's not
really any sort of thing at all to be concerned about politically.
So, Taylor not displaying the Akura Bloodline Legacy is honestly not any sort of issue in regards to Akura Legitimacy outside of the hypothetical "Hebert For Shadow Goddess President" but that's unlikely for- let's just say "several reasons" and leave it at that.
In terms of Marriage Politics, external actors are entirely a non-issue for the summarized issue of "Not Their Circus Not Their Monkeys", where it would take some sort of
really archaic asshole to make
any sort of fuss about it, and they'd have to be
at least as powerful as a Monarch for said fuss to have any real barring on anything that could possibly matter in terms of putting pressure on Taylor to get some sort of marriage to an Akura.
For internal actors aka Akura Clan Politics Below The Level That Malice Cares About, well.
Taylor is/was the personal disciple of Charity, the Heart Sage, is the personal friend and right hand of Mercy, the Akura Heir, and was involved in a long term scheme to manipulate the Dragons into wasting a bunch of resources crippling one of their rising stars for the Uncrowned King Tournament, which I emphasize succeeded,
and became one of the Uncrowned IIRC.
All that alone, let alone together, would make Taylor untouchable in terms of Akura Clan Internal Politics, especially after Harmony screwed up so bad it was honestly a relief when Lindon killed him, but her becoming an Overlord, and then an Overlord Sage, makes the idea of anyone within the Akura Clan who isn't Mercy, Charity, or Malice trying to pressure Taylor regarding anything is honestly completely laughable.
Cradle is a world that respects known strength, and Taylor is currently in the top point 1 percent in terms of strength, with her journey to Archelord and thus Sage Proper and then Monarch effectively ensured unless someone kills her.
And good luck doing that to someone with the Shadow Icon, who will also soon have the Oracle Icon.
So, in summary: It doesn't really matter that Taylor doesn't have the Akura Bloodline Legacy, and anyone trying to pressure Taylor into a marriage for any sort of reason is probably suicidally stupid and is either that dumb or is trying to die by Magic Ninja Cop.