I had an idea for a story and I'm wondering if its out there already~ atau if my characters are mary sues? (I don't want to be a copy-cat)

Its from the villian perspective and there's four people living with the master:
the housekeeper- Mistress Marta who willingly turns a blind eye to any and all evilness around her
Spider- one of three asassin/mercenary types, the strategist of the three
Hane(name disputed)- the musceled go kill 'em type asassin
and (no name yet-)the hot head who hates everyone.

The "good" house that the master opposes in the whole story:
Master(this ones a woman) that has a past with the other master
Borno/Bronto~ the male equivalent of Mistress Marta (evil!!!)
Arden~ who labah-labah, laba-laba is sent to kill
(???)~ Ardens brother *very skilled at killing
(???)~scholar type

As i berkata it would be helpful to know if something like this has been written if any of these characters is a Mary Sue-type, and maybe a judul and some names... :) Thx