what myths are you referring to?

it may be more help to link sources that support your conclusions

i admit a lack of historical context to many texts i have read and my only exposure to 'the thirty' is through plato without any supplemental research of my own on the subject so my prejudices are his

because of this i did as you suggested and did a search for 'thirty tyrants' and i only found material that conflicted and confused your comment as here stated

from the wiki(o):

Due to their desire to remain in complete control
over Athens, the Thirty sought to exile or kill anyone
who outwardly opposed their regime. Socrates was one of
the several citizens who chose to oppose the oligarchy,
and with that opposition came the endangerment of his life.

which appears to state the opposite of what you claimed

also from the wiki you can see that the leader of the thirty, critias, was indeed a former pupil of socrates, but the relationship seems to have ended and as such noting critias was a pupil of socrates seems to be judging the teacher for the ills of the student

plato talks about the thirty a number of times..

from his seventh letter(i):

In my youth I went through the same
experience as many other men. I fancied
that if, early in life, I became my own
master, I should at once embark on a
political career.

And I found myself confronted with the
following occurrences in the public
affairs of my own city. The existing
constitution being generally condemned,
a revolution took place, and fifty-one men
came to the front as rulers of the
revolutionary government, namely eleven in
the city and ten in the Peiraeus-each of
these bodies being in charge of the market
and municipal matters-while thirty were
appointed rulers with full powers over
public affairs as a whole.

Some of these were relatives and acquaintances
of mine, and they at once invited me to share
in their doings, as something to which I had
a claim. The effect on me was not surprising
in the case of a young man.

I considered that they would, of course, so
manage the State as to bring men out of a bad
way of life into a good one. So I watched them
very closely to see what they would do.

And seeing, as I did, that in quite a short time
they made the former government seem by comparison
something precious as gold-for among other things
they tried to send a friend of mine, the aged
Socrates, whom I should scarcely scruple to describe
as the most upright man of that day, with some other
persons to carry off one of the citizens by force to
execution, in order that, whether he wished it, or not,
he might share the guilt of their conduct; but he
would not obey them, risking all consequences in
preference to becoming a partner in their iniquitous
deeds-seeing all these things and others of the same
kind on a considerable scale, I disapproved of their
proceedings, and withdrew from any connection with
the abuses of the time.

here we have a politically minded plato with a sudden opportunity to become a politician because his friends, socratic pupil associations, and family just performed a coup on what was considered a generally reviled existing governing body

but decided to wait a bit and found his reluctance supported as they quickly became tyrants making the previously reviled government 'seem by comparison something precious as gold'

then he goes on to recount how socrates put himself at great risk to refuse to gather dissidents for execution

a story that plato recounts in socrates' apology(ii) in first person through socrates:

But when the oligarchy of the Thirty was in power,
they sent for me and four others into the rotunda,
and bade us bring Leon the Salaminian from Salamis,
as they wanted to execute him.

This was a specimen of the sort of commands which
they were always giving with the view of implicating
as many as possible in their crimes; and then I
showed, not in words only, but in deed, that, if I
may be allowed to use such an expression, I cared
not a straw for death, and that my only fear was the
fear of doing an unrighteous or unholy thing.

For the strong arm of that oppressive power did not
frighten me into doing wrong; and when we came out
of the rotunda the other four went to Salamis and
fetched Leon, but I went quietly home.

For which I might have lost my life, had not the
power of the Thirty shortly afterwards come to an
end. And to this many will witness.

so according to plato, and apparently many who will bear witness, socrates refused a call from the thirty to execute one who spoke against their tyranny

from salamis' wiki(iii):

From these texts, it is clear that Leon of Salamis
had an honorable reputation, he was put to death by
the Thirty, and his execution was publicly recognized
as unjust and unwarranted.

and a widely believed wrongful execution at that

investigating your claims has found me wholly opposing conclusions

i am indifferent to the righteousness of socrates the man but your slander stands unsupported

there is plenty in plato that could be argued the work of lunacy but i am unable to find your purported support for this tyranny

this quote from the apology(ii) is one of my favourites:

Is there not here conceit of knowledge, which is a
disgraceful sort of ignorance? And this is the point
in which, as I think, I am superior to men in general,
and in which I might perhaps fancy myself wiser than
other men, - that whereas I know but little of the
world below, I do not suppose that I know

i free myself from thinking i know that which i am without knowledge of

(o) https://en.wikipedia.org/wiki/Thirty_Tyrants

(i) http://classics.mit.edu/Plato/seventh_letter.html

(ii) http://classics.mit.edu/Plato/apology.html

(iii) https://en.wikipedia.org/wiki/Leon_of_Salamis