After my play, I would say than sissication isn't really there... there is transformation, mental changes, but you don't turn the character into a sissy... he/she does it for himself/herself with no explanation of how...
Dev should understand than estrogen doesn't turn a man into a sissy...
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and
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according to Merriam-Webster.
Turning a male feminine in looks and mind does,
de facto, turn him into a sissy.
As for who is the cause of it, Latin can help us with the suffix "
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" (from Merriam-Webster)
Clearly, the word "
sissification" translates to "
the making of a man that is feminine in appearance or manner", without any care for who is responsible for it.
A could sissify B, just like B could sissify himself, or become a sissy for whatever reason.
The only thing that matters for something to qualify as sissification is the starting point being a non-effeminate man and the ending point being an effeminate man.
Now, for the causes.
Let's see what
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(and
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) has to say about estrogen.
Estrogen is the hormone part of the "feminizing hormone therapy", which, paired with the definition above ("
the making of a man that is feminine in appearance or manner") leaves us with the logical conclusion that "
Estrogen, by making a man more feminine in appearance, causes his sissification".