Trice is classes as a nickname of Theresa, and the meaning of that name is reaper.
Yes, St. Teresa of Avila is sometimes known as "The Great St. Teresa."
Tessie is typically a nickname or diminutive form of the name Theresa or Tessa.
If you like 'Nan' as a nickname, then yes, it is a good nickname.
A good nickname for what? Sounds a bit pansy
Chris or CJ could be good nicknames for Christian.
It does not require a nickname.
A good nickname for Zekrom would be "Black Dragon".
Jaz might be a good nickname
A good nickname for someone named Christian could be "Chris" or "Cris" for short.
Kenster, Ken, Kenny...
Lee is a good nickname because it is part of Emi ly (Lee).