.. The
Viz references the
Nine Tailed Demon Spirit Fox
You must be registered for see links
as
— a
"spirit" — which implies that the other
Tailed Beasts', are also tangentially likely
"spirits" ...
Therein, a specific retroactive question arises ... Why were the
Tailed Beasts' referenced as literal life splits composed of
chakra? I think that the answer to that question is the likely fact that the author is playing a
specific trick on words ..
ie., the term
"chakra" can
interchangeably be slipped for
a "spirit".
Pertaining the topic of this thread, I don't think that the
Tailed Beasts' age. Spiritual beings often lack a natural aging process in many fictional works, and this is exemplified by the fact that the
Tailed Beasts' existed during Hagoromo Ōtsōtsūki's advanced years, which is likely several
1,000s of years ago, and it seems that they did exude some signs of natural growth (as
The Nine Tails was visibly a baby during the waning years of Hagoromo Ōtsōtsūki) — however, if we approximate by the timeline — the
9 Tailed Beasts' should've
significantly exceeded thier youthful years, and
spear-headed into the glass of old age — but .. it feels like the natural limits of old age, didn't
implicitly affect them.
Supplementally, I don't think that they can
"train" to enhance thier spiritual, and physical abilities
.. as .. if such a method truly existed, than the
Jinchūurikis' would've likely tried it at some point in the series so
.. unless .. the author applies a new formula to the mix, that enables them to enhance thier spiritual, and physical abilities in
Bōruto .. I don't see that happening.